Re: ceph osd commit latency increase over time, until restart

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Hi Alexander,

I think op_w_process_latency includes replication times, not 100% sure though.

So restarting other nodes might affect latencies at this specific OSD.


Thanks,

Igot

On 2/16/2019 11:29 AM, Alexandre DERUMIER wrote:
There are 10 OSDs in these systems with 96GB of memory in total. We are
runnigh with memory target on 6G right now to make sure there is no
leakage. If this runs fine for a longer period we will go to 8GB per OSD
so it will max out on 80GB leaving 16GB as spare.
Thanks Wido. I send results monday with my increased memory



@Igor:

I have also notice, that sometime when I have bad latency on an osd on node1 (restarted 12h ago for example).
(op_w_process_latency).

If I restart osds on other nodes (last restart some days ago, so with bigger latency), it's reducing latency on osd of node1 too.

does "op_w_process_latency" counter include replication time ?

----- Mail original -----
De: "Wido den Hollander" <wido@xxxxxxxx>
À: "aderumier" <aderumier@xxxxxxxxx>
Cc: "Igor Fedotov" <ifedotov@xxxxxxx>, "ceph-users" <ceph-users@xxxxxxxxxxxxxx>, "ceph-devel" <ceph-devel@xxxxxxxxxxxxxxx>
Envoyé: Vendredi 15 Février 2019 14:59:30
Objet: Re:  ceph osd commit latency increase over time, until restart

On 2/15/19 2:54 PM, Alexandre DERUMIER wrote:
Just wanted to chime in, I've seen this with Luminous+BlueStore+NVMe
OSDs as well. Over time their latency increased until we started to
notice I/O-wait inside VMs.
I'm also notice it in the vms. BTW, what it your nvme disk size ?
Samsung PM983 3.84TB SSDs in both clusters.


A restart fixed it. We also increased memory target from 4G to 6G on
these OSDs as the memory would allow it.
I have set memory to 6GB this morning, with 2 osds of 3TB for 6TB nvme.
(my last test was 8gb with 1osd of 6TB, but that didn't help)
There are 10 OSDs in these systems with 96GB of memory in total. We are
runnigh with memory target on 6G right now to make sure there is no
leakage. If this runs fine for a longer period we will go to 8GB per OSD
so it will max out on 80GB leaving 16GB as spare.

As these OSDs were all restarted earlier this week I can't tell how it
will hold up over a longer period. Monitoring (Zabbix) shows the latency
is fine at the moment.

Wido


----- Mail original -----
De: "Wido den Hollander" <wido@xxxxxxxx>
À: "Alexandre Derumier" <aderumier@xxxxxxxxx>, "Igor Fedotov" <ifedotov@xxxxxxx>
Cc: "ceph-users" <ceph-users@xxxxxxxxxxxxxx>, "ceph-devel" <ceph-devel@xxxxxxxxxxxxxxx>
Envoyé: Vendredi 15 Février 2019 14:50:34
Objet: Re:  ceph osd commit latency increase over time, until restart

On 2/15/19 2:31 PM, Alexandre DERUMIER wrote:
Thanks Igor.

I'll try to create multiple osds by nvme disk (6TB) to see if behaviour is different.

I have other clusters (same ceph.conf), but with 1,6TB drives, and I don't see this latency problem.


Just wanted to chime in, I've seen this with Luminous+BlueStore+NVMe
OSDs as well. Over time their latency increased until we started to
notice I/O-wait inside VMs.

A restart fixed it. We also increased memory target from 4G to 6G on
these OSDs as the memory would allow it.

But we noticed this on two different 12.2.10/11 clusters.

A restart made the latency drop. Not only the numbers, but the
real-world latency as experienced by a VM as well.

Wido





----- Mail original -----
De: "Igor Fedotov" <ifedotov@xxxxxxx>
Cc: "ceph-users" <ceph-users@xxxxxxxxxxxxxx>, "ceph-devel" <ceph-devel@xxxxxxxxxxxxxxx>
Envoyé: Vendredi 15 Février 2019 13:47:57
Objet: Re:  ceph osd commit latency increase over time, until restart

Hi Alexander,

I've read through your reports, nothing obvious so far.

I can only see several times average latency increase for OSD write ops
(in seconds)
0.002040060 (first hour) vs.

0.002483516 (last 24 hours) vs.
0.008382087 (last hour)

subop_w_latency:
0.000478934 (first hour) vs.
0.000537956 (last 24 hours) vs.
0.003073475 (last hour)

and OSD read ops, osd_r_latency:

0.000408595 (first hour)
0.000709031 (24 hours)
0.004979540 (last hour)

What's interesting is that such latency differences aren't observed at
neither BlueStore level (any _lat params under "bluestore" section) nor
rocksdb one.

Which probably means that the issue is rather somewhere above BlueStore.

Suggest to proceed with perf dumps collection to see if the picture
stays the same.

W.r.t. memory usage you observed I see nothing suspicious so far - No
decrease in RSS report is a known artifact that seems to be safe.

Thanks,
Igor

On 2/13/2019 11:42 AM, Alexandre DERUMIER wrote:
Hi Igor,

Thanks again for helping !



I have upgrade to last mimic this weekend, and with new autotune memory,
I have setup osd_memory_target to 8G. (my nvme are 6TB)


I have done a lot of perf dump and mempool dump and ps of process to
see rss memory at different hours,
here the reports for osd.0:

http://odisoweb1.odiso.net/perfanalysis/


osd has been started the 12-02-2019 at 08:00

first report after 1h running
http://odisoweb1.odiso.net/perfanalysis/osd.0.12-02-2018.09:30.perf.txt

http://odisoweb1.odiso.net/perfanalysis/osd.0.12-02-2018.09:30.dump_mempools.txt
http://odisoweb1.odiso.net/perfanalysis/osd.0.12-02-2018.09:30.ps.txt



report after 24 before counter resets

http://odisoweb1.odiso.net/perfanalysis/osd.0.13-02-2018.08:00.perf.txt

http://odisoweb1.odiso.net/perfanalysis/osd.0.13-02-2018.08:00.dump_mempools.txt
http://odisoweb1.odiso.net/perfanalysis/osd.0.13-02-2018.08:00.ps.txt

report 1h after counter reset
http://odisoweb1.odiso.net/perfanalysis/osd.0.13-02-2018.09:00.perf.txt

http://odisoweb1.odiso.net/perfanalysis/osd.0.13-02-2018.09:00.dump_mempools.txt
http://odisoweb1.odiso.net/perfanalysis/osd.0.13-02-2018.09:00.ps.txt




I'm seeing the bluestore buffer bytes memory increasing up to 4G
around 12-02-2019 at 14:00
http://odisoweb1.odiso.net/perfanalysis/graphs2.png
Then after that, slowly decreasing.


Another strange thing,
I'm seeing total bytes at 5G at 12-02-2018.13:30

http://odisoweb1.odiso.net/perfanalysis/osd.0.12-02-2018.13:30.dump_mempools.txt
Then is decreasing over time (around 3,7G this morning), but RSS is
still at 8G

I'm graphing mempools counters too since yesterday, so I'll able to
track them over time.
----- Mail original -----
De: "Igor Fedotov" <ifedotov@xxxxxxx>
À: "Alexandre Derumier" <aderumier@xxxxxxxxx>
Cc: "Sage Weil" <sage@xxxxxxxxxxxx>, "ceph-users"
<ceph-users@xxxxxxxxxxxxxx>, "ceph-devel" <ceph-devel@xxxxxxxxxxxxxxx>
Envoyé: Lundi 11 Février 2019 12:03:17
Objet: Re:  ceph osd commit latency increase over time,
until restart
On 2/8/2019 6:57 PM, Alexandre DERUMIER wrote:
another mempool dump after 1h run. (latency ok)

Biggest difference:

before restart
-------------
"bluestore_cache_other": {
"items": 48661920,
"bytes": 1539544228
},
"bluestore_cache_data": {
"items": 54,
"bytes": 643072
},
(other caches seem to be quite low too, like bluestore_cache_other
take all the memory)

After restart
-------------
"bluestore_cache_other": {
"items": 12432298,
"bytes": 500834899
},
"bluestore_cache_data": {
"items": 40084,
"bytes": 1056235520
},

This is fine as cache is warming after restart and some rebalancing
between data and metadata might occur.

What relates to allocator and most probably to fragmentation growth is :

"bluestore_alloc": {
"items": 165053952,
"bytes": 165053952
},

which had been higher before the reset (if I got these dumps' order
properly)

"bluestore_alloc": {
"items": 210243456,
"bytes": 210243456
},

But as I mentioned - I'm not 100% sure this might cause such a huge
latency increase...

Do you have perf counters dump after the restart?

Could you collect some more dumps - for both mempool and perf counters?

So ideally I'd like to have:

1) mempool/perf counters dumps after the restart (1hour is OK)

2) mempool/perf counters dumps in 24+ hours after restart

3) reset perf counters after 2), wait for 1 hour (and without OSD
restart) and dump mempool/perf counters again.

So we'll be able to learn both allocator mem usage growth and operation
latency distribution for the following periods:

a) 1st hour after restart

b) 25th hour.


Thanks,

Igor


full mempool dump after restart
-------------------------------

{
"mempool": {
"by_pool": {
"bloom_filter": {
"items": 0,
"bytes": 0
},
"bluestore_alloc": {
"items": 165053952,
"bytes": 165053952
},
"bluestore_cache_data": {
"items": 40084,
"bytes": 1056235520
},
"bluestore_cache_onode": {
"items": 22225,
"bytes": 14935200
},
"bluestore_cache_other": {
"items": 12432298,
"bytes": 500834899
},
"bluestore_fsck": {
"items": 0,
"bytes": 0
},
"bluestore_txc": {
"items": 11,
"bytes": 8184
},
"bluestore_writing_deferred": {
"items": 5047,
"bytes": 22673736
},
"bluestore_writing": {
"items": 91,
"bytes": 1662976
},
"bluefs": {
"items": 1907,
"bytes": 95600
},
"buffer_anon": {
"items": 19664,
"bytes": 25486050
},
"buffer_meta": {
"items": 46189,
"bytes": 2956096
},
"osd": {
"items": 243,
"bytes": 3089016
},
"osd_mapbl": {
"items": 17,
"bytes": 214366
},
"osd_pglog": {
"items": 889673,
"bytes": 367160400
},
"osdmap": {
"items": 3803,
"bytes": 224552
},
"osdmap_mapping": {
"items": 0,
"bytes": 0
},
"pgmap": {
"items": 0,
"bytes": 0
},
"mds_co": {
"items": 0,
"bytes": 0
},
"unittest_1": {
"items": 0,
"bytes": 0
},
"unittest_2": {
"items": 0,
"bytes": 0
}
},
"total": {
"items": 178515204,
"bytes": 2160630547
}
}
}

----- Mail original -----
De: "aderumier" <aderumier@xxxxxxxxx>
À: "Igor Fedotov" <ifedotov@xxxxxxx>
Cc: "Stefan Priebe, Profihost AG" <s.priebe@xxxxxxxxxxxx>, "Mark
Nelson" <mnelson@xxxxxxxxxx>, "Sage Weil" <sage@xxxxxxxxxxxx>,
"ceph-users" <ceph-users@xxxxxxxxxxxxxx>, "ceph-devel"
<ceph-devel@xxxxxxxxxxxxxxx>
Envoyé: Vendredi 8 Février 2019 16:14:54
Objet: Re:  ceph osd commit latency increase over time,
until restart
I'm just seeing

StupidAllocator::_aligned_len
and

btree::btree_iterator<btree::btree_node<btree::btree_map_params<unsigned
long, unsigned long, std::less<unsigned long>, mempoo
on 1 osd, both 10%.

here the dump_mempools

{
"mempool": {
"by_pool": {
"bloom_filter": {
"items": 0,
"bytes": 0
},
"bluestore_alloc": {
"items": 210243456,
"bytes": 210243456
},
"bluestore_cache_data": {
"items": 54,
"bytes": 643072
},
"bluestore_cache_onode": {
"items": 105637,
"bytes": 70988064
},
"bluestore_cache_other": {
"items": 48661920,
"bytes": 1539544228
},
"bluestore_fsck": {
"items": 0,
"bytes": 0
},
"bluestore_txc": {
"items": 12,
"bytes": 8928
},
"bluestore_writing_deferred": {
"items": 406,
"bytes": 4792868
},
"bluestore_writing": {
"items": 66,
"bytes": 1085440
},
"bluefs": {
"items": 1882,
"bytes": 93600
},
"buffer_anon": {
"items": 138986,
"bytes": 24983701
},
"buffer_meta": {
"items": 544,
"bytes": 34816
},
"osd": {
"items": 243,
"bytes": 3089016
},
"osd_mapbl": {
"items": 36,
"bytes": 179308
},
"osd_pglog": {
"items": 952564,
"bytes": 372459684
},
"osdmap": {
"items": 3639,
"bytes": 224664
},
"osdmap_mapping": {
"items": 0,
"bytes": 0
},
"pgmap": {
"items": 0,
"bytes": 0
},
"mds_co": {
"items": 0,
"bytes": 0
},
"unittest_1": {
"items": 0,
"bytes": 0
},
"unittest_2": {
"items": 0,
"bytes": 0
}
},
"total": {
"items": 260109445,
"bytes": 2228370845
}
}
}


and the perf dump

root@ceph5-2:~# ceph daemon osd.4 perf dump
{
"AsyncMessenger::Worker-0": {
"msgr_recv_messages": 22948570,
"msgr_send_messages": 22561570,
"msgr_recv_bytes": 333085080271,
"msgr_send_bytes": 261798871204,
"msgr_created_connections": 6152,
"msgr_active_connections": 2701,
"msgr_running_total_time": 1055.197867330,
"msgr_running_send_time": 352.764480121,
"msgr_running_recv_time": 499.206831955,
"msgr_running_fast_dispatch_time": 130.982201607
},
"AsyncMessenger::Worker-1": {
"msgr_recv_messages": 18801593,
"msgr_send_messages": 18430264,
"msgr_recv_bytes": 306871760934,
"msgr_send_bytes": 192789048666,
"msgr_created_connections": 5773,
"msgr_active_connections": 2721,
"msgr_running_total_time": 816.821076305,
"msgr_running_send_time": 261.353228926,
"msgr_running_recv_time": 394.035587911,
"msgr_running_fast_dispatch_time": 104.012155720
},
"AsyncMessenger::Worker-2": {
"msgr_recv_messages": 18463400,
"msgr_send_messages": 18105856,
"msgr_recv_bytes": 187425453590,
"msgr_send_bytes": 220735102555,
"msgr_created_connections": 5897,
"msgr_active_connections": 2605,
"msgr_running_total_time": 807.186854324,
"msgr_running_send_time": 296.834435839,
"msgr_running_recv_time": 351.364389691,
"msgr_running_fast_dispatch_time": 101.215776792
},
"bluefs": {
"gift_bytes": 0,
"reclaim_bytes": 0,
"db_total_bytes": 256050724864,
"db_used_bytes": 12413042688,
"wal_total_bytes": 0,
"wal_used_bytes": 0,
"slow_total_bytes": 0,
"slow_used_bytes": 0,
"num_files": 209,
"log_bytes": 10383360,
"log_compactions": 14,
"logged_bytes": 336498688,
"files_written_wal": 2,
"files_written_sst": 4499,
"bytes_written_wal": 417989099783,
"bytes_written_sst": 213188750209
},
"bluestore": {
"kv_flush_lat": {
"avgcount": 26371957,
"sum": 26.734038497,
"avgtime": 0.000001013
},
"kv_commit_lat": {
"avgcount": 26371957,
"sum": 3397.491150603,
"avgtime": 0.000128829
},
"kv_lat": {
"avgcount": 26371957,
"sum": 3424.225189100,
"avgtime": 0.000129843
},
"state_prepare_lat": {
"avgcount": 30484924,
"sum": 3689.542105337,
"avgtime": 0.000121028
},
"state_aio_wait_lat": {
"avgcount": 30484924,
"sum": 509.864546111,
"avgtime": 0.000016725
},
"state_io_done_lat": {
"avgcount": 30484924,
"sum": 24.534052953,
"avgtime": 0.000000804
},
"state_kv_queued_lat": {
"avgcount": 30484924,
"sum": 3488.338424238,
"avgtime": 0.000114428
},
"state_kv_commiting_lat": {
"avgcount": 30484924,
"sum": 5660.437003432,
"avgtime": 0.000185679
},
"state_kv_done_lat": {
"avgcount": 30484924,
"sum": 7.763511500,
"avgtime": 0.000000254
},
"state_deferred_queued_lat": {
"avgcount": 26346134,
"sum": 666071.296856696,
"avgtime": 0.025281557
},
"state_deferred_aio_wait_lat": {
"avgcount": 26346134,
"sum": 1755.660547071,
"avgtime": 0.000066638
},
"state_deferred_cleanup_lat": {
"avgcount": 26346134,
"sum": 185465.151653703,
"avgtime": 0.007039558
},
"state_finishing_lat": {
"avgcount": 30484920,
"sum": 3.046847481,
"avgtime": 0.000000099
},
"state_done_lat": {
"avgcount": 30484920,
"sum": 13193.362685280,
"avgtime": 0.000432783
},
"throttle_lat": {
"avgcount": 30484924,
"sum": 14.634269979,
"avgtime": 0.000000480
},
"submit_lat": {
"avgcount": 30484924,
"sum": 3873.883076148,
"avgtime": 0.000127075
},
"commit_lat": {
"avgcount": 30484924,
"sum": 13376.492317331,
"avgtime": 0.000438790
},
"read_lat": {
"avgcount": 5873923,
"sum": 1817.167582057,
"avgtime": 0.000309361
},
"read_onode_meta_lat": {
"avgcount": 19608201,
"sum": 146.770464482,
"avgtime": 0.000007485
},
"read_wait_aio_lat": {
"avgcount": 13734278,
"sum": 2532.578077242,
"avgtime": 0.000184398
},
"compress_lat": {
"avgcount": 0,
"sum": 0.000000000,
"avgtime": 0.000000000
},
"decompress_lat": {
"avgcount": 1346945,
"sum": 26.227575896,
"avgtime": 0.000019471
},
"csum_lat": {
"avgcount": 28020392,
"sum": 149.587819041,
"avgtime": 0.000005338
},
"compress_success_count": 0,
"compress_rejected_count": 0,
"write_pad_bytes": 352923605,
"deferred_write_ops": 24373340,
"deferred_write_bytes": 216791842816,
"write_penalty_read_ops": 8062366,
"bluestore_allocated": 3765566013440,
"bluestore_stored": 4186255221852,
"bluestore_compressed": 39981379040,
"bluestore_compressed_allocated": 73748348928,
"bluestore_compressed_original": 165041381376,
"bluestore_onodes": 104232,
"bluestore_onode_hits": 71206874,
"bluestore_onode_misses": 1217914,
"bluestore_onode_shard_hits": 260183292,
"bluestore_onode_shard_misses": 22851573,
"bluestore_extents": 3394513,
"bluestore_blobs": 2773587,
"bluestore_buffers": 0,
"bluestore_buffer_bytes": 0,
"bluestore_buffer_hit_bytes": 62026011221,
"bluestore_buffer_miss_bytes": 995233669922,
"bluestore_write_big": 5648815,
"bluestore_write_big_bytes": 552502214656,
"bluestore_write_big_blobs": 12440992,
"bluestore_write_small": 35883770,
"bluestore_write_small_bytes": 223436965719,
"bluestore_write_small_unused": 408125,
"bluestore_write_small_deferred": 34961455,
"bluestore_write_small_pre_read": 34961455,
"bluestore_write_small_new": 514190,
"bluestore_txc": 30484924,
"bluestore_onode_reshard": 5144189,
"bluestore_blob_split": 60104,
"bluestore_extent_compress": 53347252,
"bluestore_gc_merged": 21142528,
"bluestore_read_eio": 0,
"bluestore_fragmentation_micros": 67
},
"finisher-defered_finisher": {
"queue_len": 0,
"complete_latency": {
"avgcount": 0,
"sum": 0.000000000,
"avgtime": 0.000000000
}
},
"finisher-finisher-0": {
"queue_len": 0,
"complete_latency": {
"avgcount": 26625163,
"sum": 1057.506990951,
"avgtime": 0.000039718
}
},
"finisher-objecter-finisher-0": {
"queue_len": 0,
"complete_latency": {
"avgcount": 0,
"sum": 0.000000000,
"avgtime": 0.000000000
}
},
"mutex-OSDShard.0::sdata_wait_lock": {
"wait": {
"avgcount": 0,
"sum": 0.000000000,
"avgtime": 0.000000000
}
},
"mutex-OSDShard.0::shard_lock": {
"wait": {
"avgcount": 0,
"sum": 0.000000000,
"avgtime": 0.000000000
}
},
"mutex-OSDShard.1::sdata_wait_lock": {
"wait": {
"avgcount": 0,
"sum": 0.000000000,
"avgtime": 0.000000000
}
},
"mutex-OSDShard.1::shard_lock": {
"wait": {
"avgcount": 0,
"sum": 0.000000000,
"avgtime": 0.000000000
}
},
"mutex-OSDShard.2::sdata_wait_lock": {
"wait": {
"avgcount": 0,
"sum": 0.000000000,
"avgtime": 0.000000000
}
},
"mutex-OSDShard.2::shard_lock": {
"wait": {
"avgcount": 0,
"sum": 0.000000000,
"avgtime": 0.000000000
}
},
"mutex-OSDShard.3::sdata_wait_lock": {
"wait": {
"avgcount": 0,
"sum": 0.000000000,
"avgtime": 0.000000000
}
},
"mutex-OSDShard.3::shard_lock": {
"wait": {
"avgcount": 0,
"sum": 0.000000000,
"avgtime": 0.000000000
}
},
"mutex-OSDShard.4::sdata_wait_lock": {
"wait": {
"avgcount": 0,
"sum": 0.000000000,
"avgtime": 0.000000000
}
},
"mutex-OSDShard.4::shard_lock": {
"wait": {
"avgcount": 0,
"sum": 0.000000000,
"avgtime": 0.000000000
}
},
"mutex-OSDShard.5::sdata_wait_lock": {
"wait": {
"avgcount": 0,
"sum": 0.000000000,
"avgtime": 0.000000000
}
},
"mutex-OSDShard.5::shard_lock": {
"wait": {
"avgcount": 0,
"sum": 0.000000000,
"avgtime": 0.000000000
}
},
"mutex-OSDShard.6::sdata_wait_lock": {
"wait": {
"avgcount": 0,
"sum": 0.000000000,
"avgtime": 0.000000000
}
},
"mutex-OSDShard.6::shard_lock": {
"wait": {
"avgcount": 0,
"sum": 0.000000000,
"avgtime": 0.000000000
}
},
"mutex-OSDShard.7::sdata_wait_lock": {
"wait": {
"avgcount": 0,
"sum": 0.000000000,
"avgtime": 0.000000000
}
},
"mutex-OSDShard.7::shard_lock": {
"wait": {
"avgcount": 0,
"sum": 0.000000000,
"avgtime": 0.000000000
}
},
"objecter": {
"op_active": 0,
"op_laggy": 0,
"op_send": 0,
"op_send_bytes": 0,
"op_resend": 0,
"op_reply": 0,
"op": 0,
"op_r": 0,
"op_w": 0,
"op_rmw": 0,
"op_pg": 0,
"osdop_stat": 0,
"osdop_create": 0,
"osdop_read": 0,
"osdop_write": 0,
"osdop_writefull": 0,
"osdop_writesame": 0,
"osdop_append": 0,
"osdop_zero": 0,
"osdop_truncate": 0,
"osdop_delete": 0,
"osdop_mapext": 0,
"osdop_sparse_read": 0,
"osdop_clonerange": 0,
"osdop_getxattr": 0,
"osdop_setxattr": 0,
"osdop_cmpxattr": 0,
"osdop_rmxattr": 0,
"osdop_resetxattrs": 0,
"osdop_tmap_up": 0,
"osdop_tmap_put": 0,
"osdop_tmap_get": 0,
"osdop_call": 0,
"osdop_watch": 0,
"osdop_notify": 0,
"osdop_src_cmpxattr": 0,
"osdop_pgls": 0,
"osdop_pgls_filter": 0,
"osdop_other": 0,
"linger_active": 0,
"linger_send": 0,
"linger_resend": 0,
"linger_ping": 0,
"poolop_active": 0,
"poolop_send": 0,
"poolop_resend": 0,
"poolstat_active": 0,
"poolstat_send": 0,
"poolstat_resend": 0,
"statfs_active": 0,
"statfs_send": 0,
"statfs_resend": 0,
"command_active": 0,
"command_send": 0,
"command_resend": 0,
"map_epoch": 105913,
"map_full": 0,
"map_inc": 828,
"osd_sessions": 0,
"osd_session_open": 0,
"osd_session_close": 0,
"osd_laggy": 0,
"omap_wr": 0,
"omap_rd": 0,
"omap_del": 0
},
"osd": {
"op_wip": 0,
"op": 16758102,
"op_in_bytes": 238398820586,
"op_out_bytes": 165484999463,
"op_latency": {
"avgcount": 16758102,
"sum": 38242.481640842,
"avgtime": 0.002282029
},
"op_process_latency": {
"avgcount": 16758102,
"sum": 28644.906310687,
"avgtime": 0.001709316
},
"op_prepare_latency": {
"avgcount": 16761367,
"sum": 3489.856599934,
"avgtime": 0.000208208
},
"op_r": 6188565,
"op_r_out_bytes": 165484999463,
"op_r_latency": {
"avgcount": 6188565,
"sum": 4507.365756792,
"avgtime": 0.000728337
},
"op_r_process_latency": {
"avgcount": 6188565,
"sum": 942.363063429,
"avgtime": 0.000152274
},
"op_r_prepare_latency": {
"avgcount": 6188644,
"sum": 982.866710389,
"avgtime": 0.000158817
},
"op_w": 10546037,
"op_w_in_bytes": 238334329494,
"op_w_latency": {
"avgcount": 10546037,
"sum": 33160.719998316,
"avgtime": 0.003144377
},
"op_w_process_latency": {
"avgcount": 10546037,
"sum": 27668.702029030,
"avgtime": 0.002623611
},
"op_w_prepare_latency": {
"avgcount": 10548652,
"sum": 2499.688609173,
"avgtime": 0.000236967
},
"op_rw": 23500,
"op_rw_in_bytes": 64491092,
"op_rw_out_bytes": 0,
"op_rw_latency": {
"avgcount": 23500,
"sum": 574.395885734,
"avgtime": 0.024442378
},
"op_rw_process_latency": {
"avgcount": 23500,
"sum": 33.841218228,
"avgtime": 0.001440051
},
"op_rw_prepare_latency": {
"avgcount": 24071,
"sum": 7.301280372,
"avgtime": 0.000303322
},
"op_before_queue_op_lat": {
"avgcount": 57892986,
"sum": 1502.117718889,
"avgtime": 0.000025946
},
"op_before_dequeue_op_lat": {
"avgcount": 58091683,
"sum": 45194.453254037,
"avgtime": 0.000777984
},
"subop": 19784758,
"subop_in_bytes": 547174969754,
"subop_latency": {
"avgcount": 19784758,
"sum": 13019.714424060,
"avgtime": 0.000658067
},
"subop_w": 19784758,
"subop_w_in_bytes": 547174969754,
"subop_w_latency": {
"avgcount": 19784758,
"sum": 13019.714424060,
"avgtime": 0.000658067
},
"subop_pull": 0,
"subop_pull_latency": {
"avgcount": 0,
"sum": 0.000000000,
"avgtime": 0.000000000
},
"subop_push": 0,
"subop_push_in_bytes": 0,
"subop_push_latency": {
"avgcount": 0,
"sum": 0.000000000,
"avgtime": 0.000000000
},
"pull": 0,
"push": 2003,
"push_out_bytes": 5560009728,
"recovery_ops": 1940,
"loadavg": 118,
"buffer_bytes": 0,
"history_alloc_Mbytes": 0,
"history_alloc_num": 0,
"cached_crc": 0,
"cached_crc_adjusted": 0,
"missed_crc": 0,
"numpg": 243,
"numpg_primary": 82,
"numpg_replica": 161,
"numpg_stray": 0,
"numpg_removing": 0,
"heartbeat_to_peers": 10,
"map_messages": 7013,
"map_message_epochs": 7143,
"map_message_epoch_dups": 6315,
"messages_delayed_for_map": 0,
"osd_map_cache_hit": 203309,
"osd_map_cache_miss": 33,
"osd_map_cache_miss_low": 0,
"osd_map_cache_miss_low_avg": {
"avgcount": 0,
"sum": 0
},
"osd_map_bl_cache_hit": 47012,
"osd_map_bl_cache_miss": 1681,
"stat_bytes": 6401248198656,
"stat_bytes_used": 3777979072512,
"stat_bytes_avail": 2623269126144,
"copyfrom": 0,
"tier_promote": 0,
"tier_flush": 0,
"tier_flush_fail": 0,
"tier_try_flush": 0,
"tier_try_flush_fail": 0,
"tier_evict": 0,
"tier_whiteout": 1631,
"tier_dirty": 22360,
"tier_clean": 0,
"tier_delay": 0,
"tier_proxy_read": 0,
"tier_proxy_write": 0,
"agent_wake": 0,
"agent_skip": 0,
"agent_flush": 0,
"agent_evict": 0,
"object_ctx_cache_hit": 16311156,
"object_ctx_cache_total": 17426393,
"op_cache_hit": 0,
"osd_tier_flush_lat": {
"avgcount": 0,
"sum": 0.000000000,
"avgtime": 0.000000000
},
"osd_tier_promote_lat": {
"avgcount": 0,
"sum": 0.000000000,
"avgtime": 0.000000000
},
"osd_tier_r_lat": {
"avgcount": 0,
"sum": 0.000000000,
"avgtime": 0.000000000
},
"osd_pg_info": 30483113,
"osd_pg_fastinfo": 29619885,
"osd_pg_biginfo": 81703
},
"recoverystate_perf": {
"initial_latency": {
"avgcount": 243,
"sum": 6.869296500,
"avgtime": 0.028268709
},
"started_latency": {
"avgcount": 1125,
"sum": 13551384.917335850,
"avgtime": 12045.675482076
},
"reset_latency": {
"avgcount": 1368,
"sum": 1101.727799040,
"avgtime": 0.805356578
},
"start_latency": {
"avgcount": 1368,
"sum": 0.002014799,
"avgtime": 0.000001472
},
"primary_latency": {
"avgcount": 507,
"sum": 4575560.638823428,
"avgtime": 9024.774435549
},
"peering_latency": {
"avgcount": 550,
"sum": 499.372283616,
"avgtime": 0.907949606
},
"backfilling_latency": {
"avgcount": 0,
"sum": 0.000000000,
"avgtime": 0.000000000
},
"waitremotebackfillreserved_latency": {
"avgcount": 0,
"sum": 0.000000000,
"avgtime": 0.000000000
},
"waitlocalbackfillreserved_latency": {
"avgcount": 0,
"sum": 0.000000000,
"avgtime": 0.000000000
},
"notbackfilling_latency": {
"avgcount": 0,
"sum": 0.000000000,
"avgtime": 0.000000000
},
"repnotrecovering_latency": {
"avgcount": 1009,
"sum": 8975301.082274411,
"avgtime": 8895.243887288
},
"repwaitrecoveryreserved_latency": {
"avgcount": 420,
"sum": 99.846056520,
"avgtime": 0.237728706
},
"repwaitbackfillreserved_latency": {
"avgcount": 0,
"sum": 0.000000000,
"avgtime": 0.000000000
},
"reprecovering_latency": {
"avgcount": 420,
"sum": 241.682764382,
"avgtime": 0.575435153
},
"activating_latency": {
"avgcount": 507,
"sum": 16.893347339,
"avgtime": 0.033320211
},
"waitlocalrecoveryreserved_latency": {
"avgcount": 199,
"sum": 672.335512769,
"avgtime": 3.378570415
},
"waitremoterecoveryreserved_latency": {
"avgcount": 199,
"sum": 213.536439363,
"avgtime": 1.073047433
},
"recovering_latency": {
"avgcount": 199,
"sum": 79.007696479,
"avgtime": 0.397023600
},
"recovered_latency": {
"avgcount": 507,
"sum": 14.000732748,
"avgtime": 0.027614857
},
"clean_latency": {
"avgcount": 395,
"sum": 4574325.900371083,
"avgtime": 11580.571899673
},
"active_latency": {
"avgcount": 425,
"sum": 4575107.630123680,
"avgtime": 10764.959129702
},
"replicaactive_latency": {
"avgcount": 589,
"sum": 8975184.499049954,
"avgtime": 15238.004242869
},
"stray_latency": {
"avgcount": 818,
"sum": 800.729455666,
"avgtime": 0.978886865
},
"getinfo_latency": {
"avgcount": 550,
"sum": 15.085667048,
"avgtime": 0.027428485
},
"getlog_latency": {
"avgcount": 546,
"sum": 3.482175693,
"avgtime": 0.006377611
},
"waitactingchange_latency": {
"avgcount": 39,
"sum": 35.444551284,
"avgtime": 0.908834648
},
"incomplete_latency": {
"avgcount": 0,
"sum": 0.000000000,
"avgtime": 0.000000000
},
"down_latency": {
"avgcount": 0,
"sum": 0.000000000,
"avgtime": 0.000000000
},
"getmissing_latency": {
"avgcount": 507,
"sum": 6.702129624,
"avgtime": 0.013219190
},
"waitupthru_latency": {
"avgcount": 507,
"sum": 474.098261727,
"avgtime": 0.935105052
},
"notrecovering_latency": {
"avgcount": 0,
"sum": 0.000000000,
"avgtime": 0.000000000
}
},
"rocksdb": {
"get": 28320977,
"submit_transaction": 30484924,
"submit_transaction_sync": 26371957,
"get_latency": {
"avgcount": 28320977,
"sum": 325.900908733,
"avgtime": 0.000011507
},
"submit_latency": {
"avgcount": 30484924,
"sum": 1835.888692371,
"avgtime": 0.000060222
},
"submit_sync_latency": {
"avgcount": 26371957,
"sum": 1431.555230628,
"avgtime": 0.000054283
},
"compact": 0,
"compact_range": 0,
"compact_queue_merge": 0,
"compact_queue_len": 0,
"rocksdb_write_wal_time": {
"avgcount": 0,
"sum": 0.000000000,
"avgtime": 0.000000000
},
"rocksdb_write_memtable_time": {
"avgcount": 0,
"sum": 0.000000000,
"avgtime": 0.000000000
},
"rocksdb_write_delay_time": {
"avgcount": 0,
"sum": 0.000000000,
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},
"rocksdb_write_pre_and_post_time": {
"avgcount": 0,
"sum": 0.000000000,
"avgtime": 0.000000000
}
}
}

----- Mail original -----
De: "Igor Fedotov" <ifedotov@xxxxxxx>
À: "aderumier" <aderumier@xxxxxxxxx>
Cc: "Stefan Priebe, Profihost AG" <s.priebe@xxxxxxxxxxxx>, "Mark
Nelson" <mnelson@xxxxxxxxxx>, "Sage Weil" <sage@xxxxxxxxxxxx>,
"ceph-users" <ceph-users@xxxxxxxxxxxxxx>, "ceph-devel"
<ceph-devel@xxxxxxxxxxxxxxx>
Envoyé: Mardi 5 Février 2019 18:56:51
Objet: Re:  ceph osd commit latency increase over time,
until restart
On 2/4/2019 6:40 PM, Alexandre DERUMIER wrote:
but I don't see l_bluestore_fragmentation counter.
(but I have bluestore_fragmentation_micros)
ok, this is the same

b.add_u64(l_bluestore_fragmentation, "bluestore_fragmentation_micros",
"How fragmented bluestore free space is (free extents / max
possible number of free extents) * 1000");

Here a graph on last month, with bluestore_fragmentation_micros and
latency,
http://odisoweb1.odiso.net/latency_vs_fragmentation_micros.png
hmm, so fragmentation grows eventually and drops on OSD restarts, isn't
it? The same for other OSDs?

This proves some issue with the allocator - generally fragmentation
might grow but it shouldn't reset on restart. Looks like some intervals
aren't properly merged in run-time.

On the other side I'm not completely sure that latency degradation is
caused by that - fragmentation growth is relatively small - I don't see
how this might impact performance that high.

Wondering if you have OSD mempool monitoring (dump_mempools command
output on admin socket) reports? Do you have any historic data?

If not may I have current output and say a couple more samples with
8-12 hours interval?


Wrt to backporting bitmap allocator to mimic - we haven't had such
plans
before that but I'll discuss this at BlueStore meeting shortly.


Thanks,

Igor

----- Mail original -----
De: "Alexandre Derumier" <aderumier@xxxxxxxxx>
À: "Igor Fedotov" <ifedotov@xxxxxxx>
Cc: "Stefan Priebe, Profihost AG" <s.priebe@xxxxxxxxxxxx>, "Mark
Nelson" <mnelson@xxxxxxxxxx>, "Sage Weil" <sage@xxxxxxxxxxxx>,
"ceph-users" <ceph-users@xxxxxxxxxxxxxx>, "ceph-devel"
<ceph-devel@xxxxxxxxxxxxxxx>
Envoyé: Lundi 4 Février 2019 16:04:38
Objet: Re:  ceph osd commit latency increase over time,
until restart
Thanks Igor,

Could you please collect BlueStore performance counters right
after OSD
startup and once you get high latency.

Specifically 'l_bluestore_fragmentation' parameter is of interest.
I'm already monitoring with
"ceph daemon osd.x perf dump ", (I have 2months history will all
counters)
but I don't see l_bluestore_fragmentation counter.

(but I have bluestore_fragmentation_micros)


Also if you're able to rebuild the code I can probably make a simple
patch to track latency and some other internal allocator's
paramter to
make sure it's degraded and learn more details.
Sorry, It's a critical production cluster, I can't test on it :(
But I have a test cluster, maybe I can try to put some load on it,
and try to reproduce.


More vigorous fix would be to backport bitmap allocator from
Nautilus
and try the difference...
Any plan to backport it to mimic ? (But I can wait for Nautilus)
perf results of new bitmap allocator seem very promising from what
I've seen in PR.


----- Mail original -----
De: "Igor Fedotov" <ifedotov@xxxxxxx>
À: "Alexandre Derumier" <aderumier@xxxxxxxxx>, "Stefan Priebe,
Profihost AG" <s.priebe@xxxxxxxxxxxx>, "Mark Nelson" <mnelson@xxxxxxxxxx>
Cc: "Sage Weil" <sage@xxxxxxxxxxxx>, "ceph-users"
<ceph-users@xxxxxxxxxxxxxx>, "ceph-devel" <ceph-devel@xxxxxxxxxxxxxxx>
Envoyé: Lundi 4 Février 2019 15:51:30
Objet: Re:  ceph osd commit latency increase over time,
until restart
Hi Alexandre,

looks like a bug in StupidAllocator.

Could you please collect BlueStore performance counters right after
OSD
startup and once you get high latency.

Specifically 'l_bluestore_fragmentation' parameter is of interest.

Also if you're able to rebuild the code I can probably make a simple
patch to track latency and some other internal allocator's paramter to
make sure it's degraded and learn more details.


More vigorous fix would be to backport bitmap allocator from Nautilus
and try the difference...


Thanks,

Igor


On 2/4/2019 5:17 PM, Alexandre DERUMIER wrote:
Hi again,

I speak too fast, the problem has occured again, so it's not
tcmalloc cache size related.

I have notice something using a simple "perf top",

each time I have this problem (I have seen exactly 4 times the
same behaviour),
when latency is bad, perf top give me :

StupidAllocator::_aligned_len
and

btree::btree_iterator<btree::btree_node<btree::btree_map_params<unsigned
long, unsigned long, std::less<unsigned long>, mempoo
l::pool_allocator<(mempool::pool_index_t)1, std::pair<unsigned
long const, unsigned long> >, 256> >, std::pair<unsigned long const,
unsigned long>&, std::pair<unsigned long
const, unsigned long>*>::increment_slow()

(around 10-20% time for both)


when latency is good, I don't see them at all.


I have used the Mark wallclock profiler, here the results:

http://odisoweb1.odiso.net/gdbpmp-ok.txt

http://odisoweb1.odiso.net/gdbpmp-bad.txt


here an extract of the thread with btree::btree_iterator &&
StupidAllocator::_aligned_len

+ 100.00% clone
+ 100.00% start_thread
+ 100.00% ShardedThreadPool::WorkThreadSharded::entry()
+ 100.00% ShardedThreadPool::shardedthreadpool_worker(unsigned int)
+ 100.00% OSD::ShardedOpWQ::_process(unsigned int,
ceph::heartbeat_handle_d*)
+ 70.00% PGOpItem::run(OSD*, OSDShard*, boost::intrusive_ptr<PG>&,
ThreadPool::TPHandle&)
| + 70.00% OSD::dequeue_op(boost::intrusive_ptr<PG>,
boost::intrusive_ptr<OpRequest>, ThreadPool::TPHandle&)
| + 70.00%
PrimaryLogPG::do_request(boost::intrusive_ptr<OpRequest>&,
ThreadPool::TPHandle&)
| + 68.00% PGBackend::handle_message(boost::intrusive_ptr<OpRequest>)
| | + 68.00%
ReplicatedBackend::_handle_message(boost::intrusive_ptr<OpRequest>)
| | + 68.00%
ReplicatedBackend::do_repop(boost::intrusive_ptr<OpRequest>)
| | + 67.00% non-virtual thunk to
PrimaryLogPG::queue_transactions(std::vector<ObjectStore::Transaction,
std::allocator<ObjectStore::Transaction> >&,
boost::intrusive_ptr<OpRequest>)
| | | + 67.00%
BlueStore::queue_transactions(boost::intrusive_ptr<ObjectStore::CollectionImpl>&,
std::vector<ObjectStore::Transaction,
std::allocator<ObjectStore::Transaction> >&,
boost::intrusive_ptr<TrackedOp>, ThreadPool::TPHandle*)
| | | + 66.00%
BlueStore::_txc_add_transaction(BlueStore::TransContext*,
ObjectStore::Transaction*)
| | | | + 66.00% BlueStore::_write(BlueStore::TransContext*,
boost::intrusive_ptr<BlueStore::Collection>&,
boost::intrusive_ptr<BlueStore::Onode>&, unsigned long, unsigned long,
ceph::buffer::list&, unsigned int)
| | | | + 66.00% BlueStore::_do_write(BlueStore::TransContext*,
boost::intrusive_ptr<BlueStore::Collection>&,
boost::intrusive_ptr<BlueStore::Onode>, unsigned long, unsigned long,
ceph::buffer::list&, unsigned int)
| | | | + 65.00%
BlueStore::_do_alloc_write(BlueStore::TransContext*,
boost::intrusive_ptr<BlueStore::Collection>,
boost::intrusive_ptr<BlueStore::Onode>, BlueStore::WriteContext*)
| | | | | + 64.00% StupidAllocator::allocate(unsigned long,
unsigned long, unsigned long, long, std::vector<bluestore_pextent_t,
mempool::pool_allocator<(mempool::pool_index_t)4, bluestore_pextent_t> >*)
| | | | | | + 64.00% StupidAllocator::allocate_int(unsigned long,
unsigned long, long, unsigned long*, unsigned int*)
| | | | | | + 34.00%
btree::btree_iterator<btree::btree_node<btree::btree_map_params<unsigned
long, unsigned long, std::less<unsigned long>,
mempool::pool_allocator<(mempool::pool_index_t)1, std::pair<unsigned
long const, unsigned long> >, 256> >, std::pair<unsigned long const,
unsigned long>&, std::pair<unsigned long const, unsigned
long>*>::increment_slow()
| | | | | | + 26.00%
StupidAllocator::_aligned_len(interval_set<unsigned long,
btree::btree_map<unsigned long, unsigned long, std::less<unsigned long>,
mempool::pool_allocator<(mempool::pool_index_t)1, std::pair<unsigned
long const, unsigned long> >, 256> >::iterator, unsigned long)


----- Mail original -----
De: "Alexandre Derumier" <aderumier@xxxxxxxxx>
À: "Stefan Priebe, Profihost AG" <s.priebe@xxxxxxxxxxxx>
Cc: "Sage Weil" <sage@xxxxxxxxxxxx>, "ceph-users"
<ceph-users@xxxxxxxxxxxxxx>, "ceph-devel" <ceph-devel@xxxxxxxxxxxxxxx>
Envoyé: Lundi 4 Février 2019 09:38:11
Objet: Re:  ceph osd commit latency increase over
time, until restart
Hi,

some news:

I have tried with different transparent hugepage values (madvise,
never) : no change
I have tried to increase bluestore_cache_size_ssd to 8G: no change

I have tried to increase TCMALLOC_MAX_TOTAL_THREAD_CACHE_BYTES to
256mb : it seem to help, after 24h I'm still around 1,5ms. (need to wait
some more days to be sure)

Note that this behaviour seem to happen really faster (< 2 days)
on my big nvme drives (6TB),
my others clusters user 1,6TB ssd.

Currently I'm using only 1 osd by nvme (I don't have more than
5000iops by osd), but I'll try this week with 2osd by nvme, to see if
it's helping.

BTW, does somebody have already tested ceph without tcmalloc, with
glibc >= 2.26 (which have also thread cache) ?

Regards,

Alexandre


----- Mail original -----
De: "aderumier" <aderumier@xxxxxxxxx>
À: "Stefan Priebe, Profihost AG" <s.priebe@xxxxxxxxxxxx>
Cc: "Sage Weil" <sage@xxxxxxxxxxxx>, "ceph-users"
<ceph-users@xxxxxxxxxxxxxx>, "ceph-devel" <ceph-devel@xxxxxxxxxxxxxxx>
Envoyé: Mercredi 30 Janvier 2019 19:58:15
Objet: Re:  ceph osd commit latency increase over
time, until restart
Thanks. Is there any reason you monitor op_w_latency but not
op_r_latency but instead op_latency?

Also why do you monitor op_w_process_latency? but not
op_r_process_latency?
I monitor read too. (I have all metrics for osd sockets, and a lot
of graphs).
I just don't see latency difference on reads. (or they are very
very small vs the write latency increase)


----- Mail original -----
De: "Stefan Priebe, Profihost AG" <s.priebe@xxxxxxxxxxxx>
À: "aderumier" <aderumier@xxxxxxxxx>
Cc: "Sage Weil" <sage@xxxxxxxxxxxx>, "ceph-users"
<ceph-users@xxxxxxxxxxxxxx>, "ceph-devel" <ceph-devel@xxxxxxxxxxxxxxx>
Envoyé: Mercredi 30 Janvier 2019 19:50:20
Objet: Re:  ceph osd commit latency increase over
time, until restart
Hi,

Am 30.01.19 um 14:59 schrieb Alexandre DERUMIER:
Hi Stefan,

currently i'm in the process of switching back from jemalloc to
tcmalloc
like suggested. This report makes me a little nervous about my
change.
Well,I'm really not sure that it's a tcmalloc bug.
maybe bluestore related (don't have filestore anymore to compare)
I need to compare with bigger latencies

here an example, when all osd at 20-50ms before restart, then
after restart (at 21:15), 1ms
http://odisoweb1.odiso.net/latencybad.png

I observe the latency in my guest vm too, on disks iowait.

http://odisoweb1.odiso.net/latencybadvm.png

Also i'm currently only monitoring latency for filestore osds.
Which
exact values out of the daemon do you use for bluestore?
here my influxdb queries:

It take op_latency.sum/op_latency.avgcount on last second.


SELECT non_negative_derivative(first("op_latency.sum"),
1s)/non_negative_derivative(first("op_latency.avgcount"),1s) FROM "ceph"
WHERE "host" =~ /^([[host]])$/ AND "id" =~ /^([[osd]])$/ AND $timeFilter
GROUP BY time($interval), "host", "id" fill(previous)

SELECT non_negative_derivative(first("op_w_latency.sum"),
1s)/non_negative_derivative(first("op_w_latency.avgcount"),1s) FROM
"ceph" WHERE "host" =~ /^([[host]])$/ AND collection='osd' AND "id" =~
/^([[osd]])$/ AND $timeFilter GROUP BY time($interval), "host", "id"
fill(previous)

SELECT non_negative_derivative(first("op_w_process_latency.sum"),
1s)/non_negative_derivative(first("op_w_process_latency.avgcount"),1s)
FROM "ceph" WHERE "host" =~ /^([[host]])$/ AND collection='osd' AND "id"
=~ /^([[osd]])$/ AND $timeFilter GROUP BY time($interval), "host", "id"
fill(previous)
Thanks. Is there any reason you monitor op_w_latency but not
op_r_latency but instead op_latency?

Also why do you monitor op_w_process_latency? but not
op_r_process_latency?
greets,
Stefan

----- Mail original -----
De: "Stefan Priebe, Profihost AG" <s.priebe@xxxxxxxxxxxx>
À: "aderumier" <aderumier@xxxxxxxxx>, "Sage Weil"
<sage@xxxxxxxxxxxx>
Cc: "ceph-users" <ceph-users@xxxxxxxxxxxxxx>, "ceph-devel"
<ceph-devel@xxxxxxxxxxxxxxx>
Envoyé: Mercredi 30 Janvier 2019 08:45:33
Objet: Re:  ceph osd commit latency increase over
time, until restart
Hi,

Am 30.01.19 um 08:33 schrieb Alexandre DERUMIER:
Hi,

here some new results,
different osd/ different cluster

before osd restart latency was between 2-5ms
after osd restart is around 1-1.5ms

http://odisoweb1.odiso.net/cephperf2/bad.txt (2-5ms)
http://odisoweb1.odiso.net/cephperf2/ok.txt (1-1.5ms)
http://odisoweb1.odiso.net/cephperf2/diff.txt

 From what I see in diff, the biggest difference is in tcmalloc,
but maybe I'm wrong.
(I'm using tcmalloc 2.5-2.2)
currently i'm in the process of switching back from jemalloc to
tcmalloc
like suggested. This report makes me a little nervous about my
change.
Also i'm currently only monitoring latency for filestore osds. Which
exact values out of the daemon do you use for bluestore?

I would like to check if i see the same behaviour.

Greets,
Stefan

----- Mail original -----
De: "Sage Weil" <sage@xxxxxxxxxxxx>
À: "aderumier" <aderumier@xxxxxxxxx>
Cc: "ceph-users" <ceph-users@xxxxxxxxxxxxxx>, "ceph-devel"
<ceph-devel@xxxxxxxxxxxxxxx>
Envoyé: Vendredi 25 Janvier 2019 10:49:02
Objet: Re: ceph osd commit latency increase over time, until
restart
Can you capture a perf top or perf record to see where teh CPU
time is
going on one of the OSDs wth a high latency?

Thanks!
sage


On Fri, 25 Jan 2019, Alexandre DERUMIER wrote:

Hi,

I have a strange behaviour of my osd, on multiple clusters,

All cluster are running mimic 13.2.1,bluestore, with ssd or
nvme drivers,
workload is rbd only, with qemu-kvm vms running with librbd +
snapshot/rbd export-diff/snapshotdelete each day for backup
When the osd are refreshly started, the commit latency is
between 0,5-1ms.
But overtime, this latency increase slowly (maybe around 1ms by
day), until reaching crazy
values like 20-200ms.

Some example graphs:

http://odisoweb1.odiso.net/osdlatency1.png
http://odisoweb1.odiso.net/osdlatency2.png

All osds have this behaviour, in all clusters.

The latency of physical disks is ok. (Clusters are far to be
full loaded)
And if I restart the osd, the latency come back to 0,5-1ms.

That's remember me old tcmalloc bug, but maybe could it be a
bluestore memory bug ?
Any Hints for counters/logs to check ?


Regards,

Alexandre


_______________________________________________
ceph-users mailing list
ceph-users@xxxxxxxxxxxxxx
http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com


On 2/13/2019 11:42 AM, Alexandre DERUMIER wrote:
Hi Igor,

Thanks again for helping !



I have upgrade to last mimic this weekend, and with new autotune memory,
I have setup osd_memory_target to 8G. (my nvme are 6TB)


I have done a lot of perf dump and mempool dump and ps of process to see rss memory at different hours,
here the reports for osd.0:

http://odisoweb1.odiso.net/perfanalysis/


osd has been started the 12-02-2019 at 08:00

first report after 1h running
http://odisoweb1.odiso.net/perfanalysis/osd.0.12-02-2018.09:30.perf.txt
http://odisoweb1.odiso.net/perfanalysis/osd.0.12-02-2018.09:30.dump_mempools.txt
http://odisoweb1.odiso.net/perfanalysis/osd.0.12-02-2018.09:30.ps.txt



report after 24 before counter resets

http://odisoweb1.odiso.net/perfanalysis/osd.0.13-02-2018.08:00.perf.txt
http://odisoweb1.odiso.net/perfanalysis/osd.0.13-02-2018.08:00.dump_mempools.txt
http://odisoweb1.odiso.net/perfanalysis/osd.0.13-02-2018.08:00.ps.txt

report 1h after counter reset
http://odisoweb1.odiso.net/perfanalysis/osd.0.13-02-2018.09:00.perf.txt
http://odisoweb1.odiso.net/perfanalysis/osd.0.13-02-2018.09:00.dump_mempools.txt
http://odisoweb1.odiso.net/perfanalysis/osd.0.13-02-2018.09:00.ps.txt




I'm seeing the bluestore buffer bytes memory increasing up to 4G around 12-02-2019 at 14:00
http://odisoweb1.odiso.net/perfanalysis/graphs2.png
Then after that, slowly decreasing.


Another strange thing,
I'm seeing total bytes at 5G at 12-02-2018.13:30
http://odisoweb1.odiso.net/perfanalysis/osd.0.12-02-2018.13:30.dump_mempools.txt
Then is decreasing over time (around 3,7G this morning), but RSS is still at 8G


I'm graphing mempools counters too since yesterday, so I'll able to track them over time.

----- Mail original -----
De: "Igor Fedotov" <ifedotov@xxxxxxx>
À: "Alexandre Derumier" <aderumier@xxxxxxxxx>
Cc: "Sage Weil" <sage@xxxxxxxxxxxx>, "ceph-users" <ceph-users@xxxxxxxxxxxxxx>, "ceph-devel" <ceph-devel@xxxxxxxxxxxxxxx>
Envoyé: Lundi 11 Février 2019 12:03:17
Objet: Re:  ceph osd commit latency increase over time, until restart

On 2/8/2019 6:57 PM, Alexandre DERUMIER wrote:
another mempool dump after 1h run. (latency ok)

Biggest difference:

before restart
-------------
"bluestore_cache_other": {
"items": 48661920,
"bytes": 1539544228
},
"bluestore_cache_data": {
"items": 54,
"bytes": 643072
},
(other caches seem to be quite low too, like bluestore_cache_other take all the memory)


After restart
-------------
"bluestore_cache_other": {
"items": 12432298,
"bytes": 500834899
},
"bluestore_cache_data": {
"items": 40084,
"bytes": 1056235520
},

This is fine as cache is warming after restart and some rebalancing
between data and metadata might occur.

What relates to allocator and most probably to fragmentation growth is :

"bluestore_alloc": {
"items": 165053952,
"bytes": 165053952
},

which had been higher before the reset (if I got these dumps' order
properly)

"bluestore_alloc": {
"items": 210243456,
"bytes": 210243456
},

But as I mentioned - I'm not 100% sure this might cause such a huge
latency increase...

Do you have perf counters dump after the restart?

Could you collect some more dumps - for both mempool and perf counters?

So ideally I'd like to have:

1) mempool/perf counters dumps after the restart (1hour is OK)

2) mempool/perf counters dumps in 24+ hours after restart

3) reset perf counters after 2), wait for 1 hour (and without OSD
restart) and dump mempool/perf counters again.

So we'll be able to learn both allocator mem usage growth and operation
latency distribution for the following periods:

a) 1st hour after restart

b) 25th hour.


Thanks,

Igor


full mempool dump after restart
-------------------------------

{
"mempool": {
"by_pool": {
"bloom_filter": {
"items": 0,
"bytes": 0
},
"bluestore_alloc": {
"items": 165053952,
"bytes": 165053952
},
"bluestore_cache_data": {
"items": 40084,
"bytes": 1056235520
},
"bluestore_cache_onode": {
"items": 22225,
"bytes": 14935200
},
"bluestore_cache_other": {
"items": 12432298,
"bytes": 500834899
},
"bluestore_fsck": {
"items": 0,
"bytes": 0
},
"bluestore_txc": {
"items": 11,
"bytes": 8184
},
"bluestore_writing_deferred": {
"items": 5047,
"bytes": 22673736
},
"bluestore_writing": {
"items": 91,
"bytes": 1662976
},
"bluefs": {
"items": 1907,
"bytes": 95600
},
"buffer_anon": {
"items": 19664,
"bytes": 25486050
},
"buffer_meta": {
"items": 46189,
"bytes": 2956096
},
"osd": {
"items": 243,
"bytes": 3089016
},
"osd_mapbl": {
"items": 17,
"bytes": 214366
},
"osd_pglog": {
"items": 889673,
"bytes": 367160400
},
"osdmap": {
"items": 3803,
"bytes": 224552
},
"osdmap_mapping": {
"items": 0,
"bytes": 0
},
"pgmap": {
"items": 0,
"bytes": 0
},
"mds_co": {
"items": 0,
"bytes": 0
},
"unittest_1": {
"items": 0,
"bytes": 0
},
"unittest_2": {
"items": 0,
"bytes": 0
}
},
"total": {
"items": 178515204,
"bytes": 2160630547
}
}
}

----- Mail original -----
De: "aderumier" <aderumier@xxxxxxxxx>
À: "Igor Fedotov" <ifedotov@xxxxxxx>
Cc: "Stefan Priebe, Profihost AG" <s.priebe@xxxxxxxxxxxx>, "Mark Nelson" <mnelson@xxxxxxxxxx>, "Sage Weil" <sage@xxxxxxxxxxxx>, "ceph-users" <ceph-users@xxxxxxxxxxxxxx>, "ceph-devel" <ceph-devel@xxxxxxxxxxxxxxx>
Envoyé: Vendredi 8 Février 2019 16:14:54
Objet: Re:  ceph osd commit latency increase over time, until restart

I'm just seeing

StupidAllocator::_aligned_len
and
btree::btree_iterator<btree::btree_node<btree::btree_map_params<unsigned long, unsigned long, std::less<unsigned long>, mempoo

on 1 osd, both 10%.

here the dump_mempools

{
"mempool": {
"by_pool": {
"bloom_filter": {
"items": 0,
"bytes": 0
},
"bluestore_alloc": {
"items": 210243456,
"bytes": 210243456
},
"bluestore_cache_data": {
"items": 54,
"bytes": 643072
},
"bluestore_cache_onode": {
"items": 105637,
"bytes": 70988064
},
"bluestore_cache_other": {
"items": 48661920,
"bytes": 1539544228
},
"bluestore_fsck": {
"items": 0,
"bytes": 0
},
"bluestore_txc": {
"items": 12,
"bytes": 8928
},
"bluestore_writing_deferred": {
"items": 406,
"bytes": 4792868
},
"bluestore_writing": {
"items": 66,
"bytes": 1085440
},
"bluefs": {
"items": 1882,
"bytes": 93600
},
"buffer_anon": {
"items": 138986,
"bytes": 24983701
},
"buffer_meta": {
"items": 544,
"bytes": 34816
},
"osd": {
"items": 243,
"bytes": 3089016
},
"osd_mapbl": {
"items": 36,
"bytes": 179308
},
"osd_pglog": {
"items": 952564,
"bytes": 372459684
},
"osdmap": {
"items": 3639,
"bytes": 224664
},
"osdmap_mapping": {
"items": 0,
"bytes": 0
},
"pgmap": {
"items": 0,
"bytes": 0
},
"mds_co": {
"items": 0,
"bytes": 0
},
"unittest_1": {
"items": 0,
"bytes": 0
},
"unittest_2": {
"items": 0,
"bytes": 0
}
},
"total": {
"items": 260109445,
"bytes": 2228370845
}
}
}


and the perf dump

root@ceph5-2:~# ceph daemon osd.4 perf dump
{
"AsyncMessenger::Worker-0": {
"msgr_recv_messages": 22948570,
"msgr_send_messages": 22561570,
"msgr_recv_bytes": 333085080271,
"msgr_send_bytes": 261798871204,
"msgr_created_connections": 6152,
"msgr_active_connections": 2701,
"msgr_running_total_time": 1055.197867330,
"msgr_running_send_time": 352.764480121,
"msgr_running_recv_time": 499.206831955,
"msgr_running_fast_dispatch_time": 130.982201607
},
"AsyncMessenger::Worker-1": {
"msgr_recv_messages": 18801593,
"msgr_send_messages": 18430264,
"msgr_recv_bytes": 306871760934,
"msgr_send_bytes": 192789048666,
"msgr_created_connections": 5773,
"msgr_active_connections": 2721,
"msgr_running_total_time": 816.821076305,
"msgr_running_send_time": 261.353228926,
"msgr_running_recv_time": 394.035587911,
"msgr_running_fast_dispatch_time": 104.012155720
},
"AsyncMessenger::Worker-2": {
"msgr_recv_messages": 18463400,
"msgr_send_messages": 18105856,
"msgr_recv_bytes": 187425453590,
"msgr_send_bytes": 220735102555,
"msgr_created_connections": 5897,
"msgr_active_connections": 2605,
"msgr_running_total_time": 807.186854324,
"msgr_running_send_time": 296.834435839,
"msgr_running_recv_time": 351.364389691,
"msgr_running_fast_dispatch_time": 101.215776792
},
"bluefs": {
"gift_bytes": 0,
"reclaim_bytes": 0,
"db_total_bytes": 256050724864,
"db_used_bytes": 12413042688,
"wal_total_bytes": 0,
"wal_used_bytes": 0,
"slow_total_bytes": 0,
"slow_used_bytes": 0,
"num_files": 209,
"log_bytes": 10383360,
"log_compactions": 14,
"logged_bytes": 336498688,
"files_written_wal": 2,
"files_written_sst": 4499,
"bytes_written_wal": 417989099783,
"bytes_written_sst": 213188750209
},
"bluestore": {
"kv_flush_lat": {
"avgcount": 26371957,
"sum": 26.734038497,
"avgtime": 0.000001013
},
"kv_commit_lat": {
"avgcount": 26371957,
"sum": 3397.491150603,
"avgtime": 0.000128829
},
"kv_lat": {
"avgcount": 26371957,
"sum": 3424.225189100,
"avgtime": 0.000129843
},
"state_prepare_lat": {
"avgcount": 30484924,
"sum": 3689.542105337,
"avgtime": 0.000121028
},
"state_aio_wait_lat": {
"avgcount": 30484924,
"sum": 509.864546111,
"avgtime": 0.000016725
},
"state_io_done_lat": {
"avgcount": 30484924,
"sum": 24.534052953,
"avgtime": 0.000000804
},
"state_kv_queued_lat": {
"avgcount": 30484924,
"sum": 3488.338424238,
"avgtime": 0.000114428
},
"state_kv_commiting_lat": {
"avgcount": 30484924,
"sum": 5660.437003432,
"avgtime": 0.000185679
},
"state_kv_done_lat": {
"avgcount": 30484924,
"sum": 7.763511500,
"avgtime": 0.000000254
},
"state_deferred_queued_lat": {
"avgcount": 26346134,
"sum": 666071.296856696,
"avgtime": 0.025281557
},
"state_deferred_aio_wait_lat": {
"avgcount": 26346134,
"sum": 1755.660547071,
"avgtime": 0.000066638
},
"state_deferred_cleanup_lat": {
"avgcount": 26346134,
"sum": 185465.151653703,
"avgtime": 0.007039558
},
"state_finishing_lat": {
"avgcount": 30484920,
"sum": 3.046847481,
"avgtime": 0.000000099
},
"state_done_lat": {
"avgcount": 30484920,
"sum": 13193.362685280,
"avgtime": 0.000432783
},
"throttle_lat": {
"avgcount": 30484924,
"sum": 14.634269979,
"avgtime": 0.000000480
},
"submit_lat": {
"avgcount": 30484924,
"sum": 3873.883076148,
"avgtime": 0.000127075
},
"commit_lat": {
"avgcount": 30484924,
"sum": 13376.492317331,
"avgtime": 0.000438790
},
"read_lat": {
"avgcount": 5873923,
"sum": 1817.167582057,
"avgtime": 0.000309361
},
"read_onode_meta_lat": {
"avgcount": 19608201,
"sum": 146.770464482,
"avgtime": 0.000007485
},
"read_wait_aio_lat": {
"avgcount": 13734278,
"sum": 2532.578077242,
"avgtime": 0.000184398
},
"compress_lat": {
"avgcount": 0,
"sum": 0.000000000,
"avgtime": 0.000000000
},
"decompress_lat": {
"avgcount": 1346945,
"sum": 26.227575896,
"avgtime": 0.000019471
},
"csum_lat": {
"avgcount": 28020392,
"sum": 149.587819041,
"avgtime": 0.000005338
},
"compress_success_count": 0,
"compress_rejected_count": 0,
"write_pad_bytes": 352923605,
"deferred_write_ops": 24373340,
"deferred_write_bytes": 216791842816,
"write_penalty_read_ops": 8062366,
"bluestore_allocated": 3765566013440,
"bluestore_stored": 4186255221852,
"bluestore_compressed": 39981379040,
"bluestore_compressed_allocated": 73748348928,
"bluestore_compressed_original": 165041381376,
"bluestore_onodes": 104232,
"bluestore_onode_hits": 71206874,
"bluestore_onode_misses": 1217914,
"bluestore_onode_shard_hits": 260183292,
"bluestore_onode_shard_misses": 22851573,
"bluestore_extents": 3394513,
"bluestore_blobs": 2773587,
"bluestore_buffers": 0,
"bluestore_buffer_bytes": 0,
"bluestore_buffer_hit_bytes": 62026011221,
"bluestore_buffer_miss_bytes": 995233669922,
"bluestore_write_big": 5648815,
"bluestore_write_big_bytes": 552502214656,
"bluestore_write_big_blobs": 12440992,
"bluestore_write_small": 35883770,
"bluestore_write_small_bytes": 223436965719,
"bluestore_write_small_unused": 408125,
"bluestore_write_small_deferred": 34961455,
"bluestore_write_small_pre_read": 34961455,
"bluestore_write_small_new": 514190,
"bluestore_txc": 30484924,
"bluestore_onode_reshard": 5144189,
"bluestore_blob_split": 60104,
"bluestore_extent_compress": 53347252,
"bluestore_gc_merged": 21142528,
"bluestore_read_eio": 0,
"bluestore_fragmentation_micros": 67
},
"finisher-defered_finisher": {
"queue_len": 0,
"complete_latency": {
"avgcount": 0,
"sum": 0.000000000,
"avgtime": 0.000000000
}
},
"finisher-finisher-0": {
"queue_len": 0,
"complete_latency": {
"avgcount": 26625163,
"sum": 1057.506990951,
"avgtime": 0.000039718
}
},
"finisher-objecter-finisher-0": {
"queue_len": 0,
"complete_latency": {
"avgcount": 0,
"sum": 0.000000000,
"avgtime": 0.000000000
}
},
"mutex-OSDShard.0::sdata_wait_lock": {
"wait": {
"avgcount": 0,
"sum": 0.000000000,
"avgtime": 0.000000000
}
},
"mutex-OSDShard.0::shard_lock": {
"wait": {
"avgcount": 0,
"sum": 0.000000000,
"avgtime": 0.000000000
}
},
"mutex-OSDShard.1::sdata_wait_lock": {
"wait": {
"avgcount": 0,
"sum": 0.000000000,
"avgtime": 0.000000000
}
},
"mutex-OSDShard.1::shard_lock": {
"wait": {
"avgcount": 0,
"sum": 0.000000000,
"avgtime": 0.000000000
}
},
"mutex-OSDShard.2::sdata_wait_lock": {
"wait": {
"avgcount": 0,
"sum": 0.000000000,
"avgtime": 0.000000000
}
},
"mutex-OSDShard.2::shard_lock": {
"wait": {
"avgcount": 0,
"sum": 0.000000000,
"avgtime": 0.000000000
}
},
"mutex-OSDShard.3::sdata_wait_lock": {
"wait": {
"avgcount": 0,
"sum": 0.000000000,
"avgtime": 0.000000000
}
},
"mutex-OSDShard.3::shard_lock": {
"wait": {
"avgcount": 0,
"sum": 0.000000000,
"avgtime": 0.000000000
}
},
"mutex-OSDShard.4::sdata_wait_lock": {
"wait": {
"avgcount": 0,
"sum": 0.000000000,
"avgtime": 0.000000000
}
},
"mutex-OSDShard.4::shard_lock": {
"wait": {
"avgcount": 0,
"sum": 0.000000000,
"avgtime": 0.000000000
}
},
"mutex-OSDShard.5::sdata_wait_lock": {
"wait": {
"avgcount": 0,
"sum": 0.000000000,
"avgtime": 0.000000000
}
},
"mutex-OSDShard.5::shard_lock": {
"wait": {
"avgcount": 0,
"sum": 0.000000000,
"avgtime": 0.000000000
}
},
"mutex-OSDShard.6::sdata_wait_lock": {
"wait": {
"avgcount": 0,
"sum": 0.000000000,
"avgtime": 0.000000000
}
},
"mutex-OSDShard.6::shard_lock": {
"wait": {
"avgcount": 0,
"sum": 0.000000000,
"avgtime": 0.000000000
}
},
"mutex-OSDShard.7::sdata_wait_lock": {
"wait": {
"avgcount": 0,
"sum": 0.000000000,
"avgtime": 0.000000000
}
},
"mutex-OSDShard.7::shard_lock": {
"wait": {
"avgcount": 0,
"sum": 0.000000000,
"avgtime": 0.000000000
}
},
"objecter": {
"op_active": 0,
"op_laggy": 0,
"op_send": 0,
"op_send_bytes": 0,
"op_resend": 0,
"op_reply": 0,
"op": 0,
"op_r": 0,
"op_w": 0,
"op_rmw": 0,
"op_pg": 0,
"osdop_stat": 0,
"osdop_create": 0,
"osdop_read": 0,
"osdop_write": 0,
"osdop_writefull": 0,
"osdop_writesame": 0,
"osdop_append": 0,
"osdop_zero": 0,
"osdop_truncate": 0,
"osdop_delete": 0,
"osdop_mapext": 0,
"osdop_sparse_read": 0,
"osdop_clonerange": 0,
"osdop_getxattr": 0,
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"omap_del": 0
},
"osd": {
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"op_in_bytes": 238398820586,
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"op_latency": {
"avgcount": 16758102,
"sum": 38242.481640842,
"avgtime": 0.002282029
},
"op_process_latency": {
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"sum": 28644.906310687,
"avgtime": 0.001709316
},
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"avgcount": 16761367,
"sum": 3489.856599934,
"avgtime": 0.000208208
},
"op_r": 6188565,
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"sum": 4507.365756792,
"avgtime": 0.000728337
},
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"sum": 942.363063429,
"avgtime": 0.000152274
},
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"avgcount": 6188644,
"sum": 982.866710389,
"avgtime": 0.000158817
},
"op_w": 10546037,
"op_w_in_bytes": 238334329494,
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"avgcount": 10546037,
"sum": 33160.719998316,
"avgtime": 0.003144377
},
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"avgcount": 10546037,
"sum": 27668.702029030,
"avgtime": 0.002623611
},
"op_w_prepare_latency": {
"avgcount": 10548652,
"sum": 2499.688609173,
"avgtime": 0.000236967
},
"op_rw": 23500,
"op_rw_in_bytes": 64491092,
"op_rw_out_bytes": 0,
"op_rw_latency": {
"avgcount": 23500,
"sum": 574.395885734,
"avgtime": 0.024442378
},
"op_rw_process_latency": {
"avgcount": 23500,
"sum": 33.841218228,
"avgtime": 0.001440051
},
"op_rw_prepare_latency": {
"avgcount": 24071,
"sum": 7.301280372,
"avgtime": 0.000303322
},
"op_before_queue_op_lat": {
"avgcount": 57892986,
"sum": 1502.117718889,
"avgtime": 0.000025946
},
"op_before_dequeue_op_lat": {
"avgcount": 58091683,
"sum": 45194.453254037,
"avgtime": 0.000777984
},
"subop": 19784758,
"subop_in_bytes": 547174969754,
"subop_latency": {
"avgcount": 19784758,
"sum": 13019.714424060,
"avgtime": 0.000658067
},
"subop_w": 19784758,
"subop_w_in_bytes": 547174969754,
"subop_w_latency": {
"avgcount": 19784758,
"sum": 13019.714424060,
"avgtime": 0.000658067
},
"subop_pull": 0,
"subop_pull_latency": {
"avgcount": 0,
"sum": 0.000000000,
"avgtime": 0.000000000
},
"subop_push": 0,
"subop_push_in_bytes": 0,
"subop_push_latency": {
"avgcount": 0,
"sum": 0.000000000,
"avgtime": 0.000000000
},
"pull": 0,
"push": 2003,
"push_out_bytes": 5560009728,
"recovery_ops": 1940,
"loadavg": 118,
"buffer_bytes": 0,
"history_alloc_Mbytes": 0,
"history_alloc_num": 0,
"cached_crc": 0,
"cached_crc_adjusted": 0,
"missed_crc": 0,
"numpg": 243,
"numpg_primary": 82,
"numpg_replica": 161,
"numpg_stray": 0,
"numpg_removing": 0,
"heartbeat_to_peers": 10,
"map_messages": 7013,
"map_message_epochs": 7143,
"map_message_epoch_dups": 6315,
"messages_delayed_for_map": 0,
"osd_map_cache_hit": 203309,
"osd_map_cache_miss": 33,
"osd_map_cache_miss_low": 0,
"osd_map_cache_miss_low_avg": {
"avgcount": 0,
"sum": 0
},
"osd_map_bl_cache_hit": 47012,
"osd_map_bl_cache_miss": 1681,
"stat_bytes": 6401248198656,
"stat_bytes_used": 3777979072512,
"stat_bytes_avail": 2623269126144,
"copyfrom": 0,
"tier_promote": 0,
"tier_flush": 0,
"tier_flush_fail": 0,
"tier_try_flush": 0,
"tier_try_flush_fail": 0,
"tier_evict": 0,
"tier_whiteout": 1631,
"tier_dirty": 22360,
"tier_clean": 0,
"tier_delay": 0,
"tier_proxy_read": 0,
"tier_proxy_write": 0,
"agent_wake": 0,
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"object_ctx_cache_hit": 16311156,
"object_ctx_cache_total": 17426393,
"op_cache_hit": 0,
"osd_tier_flush_lat": {
"avgcount": 0,
"sum": 0.000000000,
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},
"osd_tier_promote_lat": {
"avgcount": 0,
"sum": 0.000000000,
"avgtime": 0.000000000
},
"osd_tier_r_lat": {
"avgcount": 0,
"sum": 0.000000000,
"avgtime": 0.000000000
},
"osd_pg_info": 30483113,
"osd_pg_fastinfo": 29619885,
"osd_pg_biginfo": 81703
},
"recoverystate_perf": {
"initial_latency": {
"avgcount": 243,
"sum": 6.869296500,
"avgtime": 0.028268709
},
"started_latency": {
"avgcount": 1125,
"sum": 13551384.917335850,
"avgtime": 12045.675482076
},
"reset_latency": {
"avgcount": 1368,
"sum": 1101.727799040,
"avgtime": 0.805356578
},
"start_latency": {
"avgcount": 1368,
"sum": 0.002014799,
"avgtime": 0.000001472
},
"primary_latency": {
"avgcount": 507,
"sum": 4575560.638823428,
"avgtime": 9024.774435549
},
"peering_latency": {
"avgcount": 550,
"sum": 499.372283616,
"avgtime": 0.907949606
},
"backfilling_latency": {
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},
"waitremotebackfillreserved_latency": {
"avgcount": 0,
"sum": 0.000000000,
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},
"waitlocalbackfillreserved_latency": {
"avgcount": 0,
"sum": 0.000000000,
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},
"notbackfilling_latency": {
"avgcount": 0,
"sum": 0.000000000,
"avgtime": 0.000000000
},
"repnotrecovering_latency": {
"avgcount": 1009,
"sum": 8975301.082274411,
"avgtime": 8895.243887288
},
"repwaitrecoveryreserved_latency": {
"avgcount": 420,
"sum": 99.846056520,
"avgtime": 0.237728706
},
"repwaitbackfillreserved_latency": {
"avgcount": 0,
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},
"reprecovering_latency": {
"avgcount": 420,
"sum": 241.682764382,
"avgtime": 0.575435153
},
"activating_latency": {
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"avgtime": 0.033320211
},
"waitlocalrecoveryreserved_latency": {
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"sum": 672.335512769,
"avgtime": 3.378570415
},
"waitremoterecoveryreserved_latency": {
"avgcount": 199,
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"avgtime": 1.073047433
},
"recovering_latency": {
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"sum": 79.007696479,
"avgtime": 0.397023600
},
"recovered_latency": {
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},
"clean_latency": {
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"sum": 4574325.900371083,
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},
"active_latency": {
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"sum": 4575107.630123680,
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},
"replicaactive_latency": {
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"sum": 8975184.499049954,
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},
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},
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},
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},
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},
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},
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},
"getmissing_latency": {
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},
"waitupthru_latency": {
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"sum": 474.098261727,
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},
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}
},
"rocksdb": {
"get": 28320977,
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"get_latency": {
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},
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},
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},
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}
}

----- Mail original -----
De: "Igor Fedotov" <ifedotov@xxxxxxx>
À: "aderumier" <aderumier@xxxxxxxxx>
Cc: "Stefan Priebe, Profihost AG" <s.priebe@xxxxxxxxxxxx>, "Mark Nelson" <mnelson@xxxxxxxxxx>, "Sage Weil" <sage@xxxxxxxxxxxx>, "ceph-users" <ceph-users@xxxxxxxxxxxxxx>, "ceph-devel" <ceph-devel@xxxxxxxxxxxxxxx>
Envoyé: Mardi 5 Février 2019 18:56:51
Objet: Re:  ceph osd commit latency increase over time, until restart

On 2/4/2019 6:40 PM, Alexandre DERUMIER wrote:
but I don't see l_bluestore_fragmentation counter.
(but I have bluestore_fragmentation_micros)
ok, this is the same

b.add_u64(l_bluestore_fragmentation, "bluestore_fragmentation_micros",
"How fragmented bluestore free space is (free extents / max possible number of free extents) * 1000");


Here a graph on last month, with bluestore_fragmentation_micros and latency,

http://odisoweb1.odiso.net/latency_vs_fragmentation_micros.png
hmm, so fragmentation grows eventually and drops on OSD restarts, isn't
it? The same for other OSDs?

This proves some issue with the allocator - generally fragmentation
might grow but it shouldn't reset on restart. Looks like some intervals
aren't properly merged in run-time.

On the other side I'm not completely sure that latency degradation is
caused by that - fragmentation growth is relatively small - I don't see
how this might impact performance that high.

Wondering if you have OSD mempool monitoring (dump_mempools command
output on admin socket) reports? Do you have any historic data?

If not may I have current output and say a couple more samples with
8-12 hours interval?


Wrt to backporting bitmap allocator to mimic - we haven't had such plans
before that but I'll discuss this at BlueStore meeting shortly.


Thanks,

Igor

----- Mail original -----
De: "Alexandre Derumier" <aderumier@xxxxxxxxx>
À: "Igor Fedotov" <ifedotov@xxxxxxx>
Cc: "Stefan Priebe, Profihost AG" <s.priebe@xxxxxxxxxxxx>, "Mark Nelson" <mnelson@xxxxxxxxxx>, "Sage Weil" <sage@xxxxxxxxxxxx>, "ceph-users" <ceph-users@xxxxxxxxxxxxxx>, "ceph-devel" <ceph-devel@xxxxxxxxxxxxxxx>
Envoyé: Lundi 4 Février 2019 16:04:38
Objet: Re:  ceph osd commit latency increase over time, until restart

Thanks Igor,

Could you please collect BlueStore performance counters right after OSD
startup and once you get high latency.

Specifically 'l_bluestore_fragmentation' parameter is of interest.
I'm already monitoring with
"ceph daemon osd.x perf dump ", (I have 2months history will all counters)

but I don't see l_bluestore_fragmentation counter.

(but I have bluestore_fragmentation_micros)


Also if you're able to rebuild the code I can probably make a simple
patch to track latency and some other internal allocator's paramter to
make sure it's degraded and learn more details.
Sorry, It's a critical production cluster, I can't test on it :(
But I have a test cluster, maybe I can try to put some load on it, and try to reproduce.



More vigorous fix would be to backport bitmap allocator from Nautilus
and try the difference...
Any plan to backport it to mimic ? (But I can wait for Nautilus)
perf results of new bitmap allocator seem very promising from what I've seen in PR.



----- Mail original -----
De: "Igor Fedotov" <ifedotov@xxxxxxx>
À: "Alexandre Derumier" <aderumier@xxxxxxxxx>, "Stefan Priebe, Profihost AG" <s.priebe@xxxxxxxxxxxx>, "Mark Nelson" <mnelson@xxxxxxxxxx>
Cc: "Sage Weil" <sage@xxxxxxxxxxxx>, "ceph-users" <ceph-users@xxxxxxxxxxxxxx>, "ceph-devel" <ceph-devel@xxxxxxxxxxxxxxx>
Envoyé: Lundi 4 Février 2019 15:51:30
Objet: Re:  ceph osd commit latency increase over time, until restart

Hi Alexandre,

looks like a bug in StupidAllocator.

Could you please collect BlueStore performance counters right after OSD
startup and once you get high latency.

Specifically 'l_bluestore_fragmentation' parameter is of interest.

Also if you're able to rebuild the code I can probably make a simple
patch to track latency and some other internal allocator's paramter to
make sure it's degraded and learn more details.


More vigorous fix would be to backport bitmap allocator from Nautilus
and try the difference...


Thanks,

Igor


On 2/4/2019 5:17 PM, Alexandre DERUMIER wrote:
Hi again,

I speak too fast, the problem has occured again, so it's not tcmalloc cache size related.


I have notice something using a simple "perf top",

each time I have this problem (I have seen exactly 4 times the same behaviour),

when latency is bad, perf top give me :

StupidAllocator::_aligned_len
and
btree::btree_iterator<btree::btree_node<btree::btree_map_params<unsigned long, unsigned long, std::less<unsigned long>, mempoo
l::pool_allocator<(mempool::pool_index_t)1, std::pair<unsigned long const, unsigned long> >, 256> >, std::pair<unsigned long const, unsigned long>&, std::pair<unsigned long
const, unsigned long>*>::increment_slow()

(around 10-20% time for both)


when latency is good, I don't see them at all.


I have used the Mark wallclock profiler, here the results:

http://odisoweb1.odiso.net/gdbpmp-ok.txt

http://odisoweb1.odiso.net/gdbpmp-bad.txt


here an extract of the thread with btree::btree_iterator && StupidAllocator::_aligned_len


+ 100.00% clone
+ 100.00% start_thread
+ 100.00% ShardedThreadPool::WorkThreadSharded::entry()
+ 100.00% ShardedThreadPool::shardedthreadpool_worker(unsigned int)
+ 100.00% OSD::ShardedOpWQ::_process(unsigned int, ceph::heartbeat_handle_d*)
+ 70.00% PGOpItem::run(OSD*, OSDShard*, boost::intrusive_ptr<PG>&, ThreadPool::TPHandle&)
| + 70.00% OSD::dequeue_op(boost::intrusive_ptr<PG>, boost::intrusive_ptr<OpRequest>, ThreadPool::TPHandle&)
| + 70.00% PrimaryLogPG::do_request(boost::intrusive_ptr<OpRequest>&, ThreadPool::TPHandle&)
| + 68.00% PGBackend::handle_message(boost::intrusive_ptr<OpRequest>)
| | + 68.00% ReplicatedBackend::_handle_message(boost::intrusive_ptr<OpRequest>)
| | + 68.00% ReplicatedBackend::do_repop(boost::intrusive_ptr<OpRequest>)
| | + 67.00% non-virtual thunk to PrimaryLogPG::queue_transactions(std::vector<ObjectStore::Transaction, std::allocator<ObjectStore::Transaction> >&, boost::intrusive_ptr<OpRequest>)
| | | + 67.00% BlueStore::queue_transactions(boost::intrusive_ptr<ObjectStore::CollectionImpl>&, std::vector<ObjectStore::Transaction, std::allocator<ObjectStore::Transaction> >&, boost::intrusive_ptr<TrackedOp>, ThreadPool::TPHandle*)
| | | + 66.00% BlueStore::_txc_add_transaction(BlueStore::TransContext*, ObjectStore::Transaction*)
| | | | + 66.00% BlueStore::_write(BlueStore::TransContext*, boost::intrusive_ptr<BlueStore::Collection>&, boost::intrusive_ptr<BlueStore::Onode>&, unsigned long, unsigned long, ceph::buffer::list&, unsigned int)
| | | | + 66.00% BlueStore::_do_write(BlueStore::TransContext*, boost::intrusive_ptr<BlueStore::Collection>&, boost::intrusive_ptr<BlueStore::Onode>, unsigned long, unsigned long, ceph::buffer::list&, unsigned int)
| | | | + 65.00% BlueStore::_do_alloc_write(BlueStore::TransContext*, boost::intrusive_ptr<BlueStore::Collection>, boost::intrusive_ptr<BlueStore::Onode>, BlueStore::WriteContext*)
| | | | | + 64.00% StupidAllocator::allocate(unsigned long, unsigned long, unsigned long, long, std::vector<bluestore_pextent_t, mempool::pool_allocator<(mempool::pool_index_t)4, bluestore_pextent_t> >*)
| | | | | | + 64.00% StupidAllocator::allocate_int(unsigned long, unsigned long, long, unsigned long*, unsigned int*)
| | | | | | + 34.00% btree::btree_iterator<btree::btree_node<btree::btree_map_params<unsigned long, unsigned long, std::less<unsigned long>, mempool::pool_allocator<(mempool::pool_index_t)1, std::pair<unsigned long const, unsigned long> >, 256> >, std::pair<unsigned long const, unsigned long>&, std::pair<unsigned long const, unsigned long>*>::increment_slow()
| | | | | | + 26.00% StupidAllocator::_aligned_len(interval_set<unsigned long, btree::btree_map<unsigned long, unsigned long, std::less<unsigned long>, mempool::pool_allocator<(mempool::pool_index_t)1, std::pair<unsigned long const, unsigned long> >, 256> >::iterator, unsigned long)



----- Mail original -----
De: "Alexandre Derumier" <aderumier@xxxxxxxxx>
À: "Stefan Priebe, Profihost AG" <s.priebe@xxxxxxxxxxxx>
Cc: "Sage Weil" <sage@xxxxxxxxxxxx>, "ceph-users" <ceph-users@xxxxxxxxxxxxxx>, "ceph-devel" <ceph-devel@xxxxxxxxxxxxxxx>
Envoyé: Lundi 4 Février 2019 09:38:11
Objet: Re:  ceph osd commit latency increase over time, until restart

Hi,

some news:

I have tried with different transparent hugepage values (madvise, never) : no change

I have tried to increase bluestore_cache_size_ssd to 8G: no change

I have tried to increase TCMALLOC_MAX_TOTAL_THREAD_CACHE_BYTES to 256mb : it seem to help, after 24h I'm still around 1,5ms. (need to wait some more days to be sure)


Note that this behaviour seem to happen really faster (< 2 days) on my big nvme drives (6TB),
my others clusters user 1,6TB ssd.

Currently I'm using only 1 osd by nvme (I don't have more than 5000iops by osd), but I'll try this week with 2osd by nvme, to see if it's helping.


BTW, does somebody have already tested ceph without tcmalloc, with glibc >= 2.26 (which have also thread cache) ?


Regards,

Alexandre


----- Mail original -----
De: "aderumier" <aderumier@xxxxxxxxx>
À: "Stefan Priebe, Profihost AG" <s.priebe@xxxxxxxxxxxx>
Cc: "Sage Weil" <sage@xxxxxxxxxxxx>, "ceph-users" <ceph-users@xxxxxxxxxxxxxx>, "ceph-devel" <ceph-devel@xxxxxxxxxxxxxxx>
Envoyé: Mercredi 30 Janvier 2019 19:58:15
Objet: Re:  ceph osd commit latency increase over time, until restart

Thanks. Is there any reason you monitor op_w_latency but not
op_r_latency but instead op_latency?

Also why do you monitor op_w_process_latency? but not op_r_process_latency?
I monitor read too. (I have all metrics for osd sockets, and a lot of graphs).

I just don't see latency difference on reads. (or they are very very small vs the write latency increase)



----- Mail original -----
De: "Stefan Priebe, Profihost AG" <s.priebe@xxxxxxxxxxxx>
À: "aderumier" <aderumier@xxxxxxxxx>
Cc: "Sage Weil" <sage@xxxxxxxxxxxx>, "ceph-users" <ceph-users@xxxxxxxxxxxxxx>, "ceph-devel" <ceph-devel@xxxxxxxxxxxxxxx>
Envoyé: Mercredi 30 Janvier 2019 19:50:20
Objet: Re:  ceph osd commit latency increase over time, until restart

Hi,

Am 30.01.19 um 14:59 schrieb Alexandre DERUMIER:
Hi Stefan,

currently i'm in the process of switching back from jemalloc to tcmalloc
like suggested. This report makes me a little nervous about my change.
Well,I'm really not sure that it's a tcmalloc bug.
maybe bluestore related (don't have filestore anymore to compare)
I need to compare with bigger latencies

here an example, when all osd at 20-50ms before restart, then after restart (at 21:15), 1ms
http://odisoweb1.odiso.net/latencybad.png

I observe the latency in my guest vm too, on disks iowait.

http://odisoweb1.odiso.net/latencybadvm.png

Also i'm currently only monitoring latency for filestore osds. Which
exact values out of the daemon do you use for bluestore?
here my influxdb queries:

It take op_latency.sum/op_latency.avgcount on last second.


SELECT non_negative_derivative(first("op_latency.sum"), 1s)/non_negative_derivative(first("op_latency.avgcount"),1s) FROM "ceph" WHERE "host" =~ /^([[host]])$/ AND "id" =~ /^([[osd]])$/ AND $timeFilter GROUP BY time($interval), "host", "id" fill(previous)


SELECT non_negative_derivative(first("op_w_latency.sum"), 1s)/non_negative_derivative(first("op_w_latency.avgcount"),1s) FROM "ceph" WHERE "host" =~ /^([[host]])$/ AND collection='osd' AND "id" =~ /^([[osd]])$/ AND $timeFilter GROUP BY time($interval), "host", "id" fill(previous)


SELECT non_negative_derivative(first("op_w_process_latency.sum"), 1s)/non_negative_derivative(first("op_w_process_latency.avgcount"),1s) FROM "ceph" WHERE "host" =~ /^([[host]])$/ AND collection='osd' AND "id" =~ /^([[osd]])$/ AND $timeFilter GROUP BY time($interval), "host", "id" fill(previous)
Thanks. Is there any reason you monitor op_w_latency but not
op_r_latency but instead op_latency?

Also why do you monitor op_w_process_latency? but not op_r_process_latency?

greets,
Stefan

----- Mail original -----
De: "Stefan Priebe, Profihost AG" <s.priebe@xxxxxxxxxxxx>
À: "aderumier" <aderumier@xxxxxxxxx>, "Sage Weil" <sage@xxxxxxxxxxxx>
Cc: "ceph-users" <ceph-users@xxxxxxxxxxxxxx>, "ceph-devel" <ceph-devel@xxxxxxxxxxxxxxx>
Envoyé: Mercredi 30 Janvier 2019 08:45:33
Objet: Re:  ceph osd commit latency increase over time, until restart

Hi,

Am 30.01.19 um 08:33 schrieb Alexandre DERUMIER:
Hi,

here some new results,
different osd/ different cluster

before osd restart latency was between 2-5ms
after osd restart is around 1-1.5ms

http://odisoweb1.odiso.net/cephperf2/bad.txt (2-5ms)
http://odisoweb1.odiso.net/cephperf2/ok.txt (1-1.5ms)
http://odisoweb1.odiso.net/cephperf2/diff.txt

 From what I see in diff, the biggest difference is in tcmalloc, but maybe I'm wrong.
(I'm using tcmalloc 2.5-2.2)
currently i'm in the process of switching back from jemalloc to tcmalloc
like suggested. This report makes me a little nervous about my change.

Also i'm currently only monitoring latency for filestore osds. Which
exact values out of the daemon do you use for bluestore?

I would like to check if i see the same behaviour.

Greets,
Stefan

----- Mail original -----
De: "Sage Weil" <sage@xxxxxxxxxxxx>
À: "aderumier" <aderumier@xxxxxxxxx>
Cc: "ceph-users" <ceph-users@xxxxxxxxxxxxxx>, "ceph-devel" <ceph-devel@xxxxxxxxxxxxxxx>
Envoyé: Vendredi 25 Janvier 2019 10:49:02
Objet: Re: ceph osd commit latency increase over time, until restart

Can you capture a perf top or perf record to see where teh CPU time is
going on one of the OSDs wth a high latency?

Thanks!
sage


On Fri, 25 Jan 2019, Alexandre DERUMIER wrote:

Hi,

I have a strange behaviour of my osd, on multiple clusters,

All cluster are running mimic 13.2.1,bluestore, with ssd or nvme drivers,
workload is rbd only, with qemu-kvm vms running with librbd + snapshot/rbd export-diff/snapshotdelete each day for backup

When the osd are refreshly started, the commit latency is between 0,5-1ms.

But overtime, this latency increase slowly (maybe around 1ms by day), until reaching crazy
values like 20-200ms.

Some example graphs:

http://odisoweb1.odiso.net/osdlatency1.png
http://odisoweb1.odiso.net/osdlatency2.png

All osds have this behaviour, in all clusters.

The latency of physical disks is ok. (Clusters are far to be full loaded)

And if I restart the osd, the latency come back to 0,5-1ms.

That's remember me old tcmalloc bug, but maybe could it be a bluestore memory bug ?

Any Hints for counters/logs to check ?


Regards,

Alexandre


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