Today we discussed about Geo-rep Status design, summary of the discussion.
- No usecase for "Deletes pending" column, should we retain it?
- No separate column for Active/Passive. Worker can be Active/Passive
only when worker is Stable(It can't be Faulty and Active)
- Rename "Not Started" status as "Created"
- Checkpoint columns will be retained in the Status output till we
support Multiple checkpoints. Three columns instead of Single
column(Completed, Checkpoint time and Completion time)
- Still we have confusion about "Files Pending" and "Files Synced", What
numbers it has to show. Georep can't map the number to exact count on disk.
Venky suggested to show Entry, Data and Metadata pending as three
columns. (Remove "Files Pending" and "Files Synced")
- Rename "Files Skipped" to "Failures"
Status output proposed:
-----------------------
MASTER NODE - Master node hostname/IP
MASTER VOL - Master volume name
MASTER BRICK - Master brick path
SLAVE USER - Slave user to which geo-rep is established.
SLAVE - Slave host and Volume name(HOST::VOL format)
STATUS - Created/Initializing../Started/Active/Passive/Stopped/Faulty
LAST SYNCED - Last synced time(Based on stime xattr)
CRAWL STATUS - Hybrid/History/Changelog
CHECKPOINT STATUS - Yes/No/ N/A
CHECKPOINT TIME - Checkpoint Set Time
CHECKPOINT COMPLETED - Checkpoint Completion Time
Not yet decided
---------------
FILES SYNCD - Number of Files Synced
FILES PENDING - Number of Files Pending
DELETES PENDING- Number of Deletes Pending
FILES SKIPPED - Number of Files skipped
ENTRIES - Create/Delete/MKDIR/RENAME etc
DATA - Data operations
METADATA - SETATTR, SETXATTR etc
Let me know your suggestions.
--
regards
Aravinda
On 02/02/2015 04:51 PM, Aravinda wrote:
Thanks Sahina, replied inline.
--
regards
Aravinda
On 02/02/2015 12:55 PM, Sahina Bose wrote:
On 01/28/2015 04:07 PM, Aravinda wrote:
Background
----------
We have `status` and `status detail` commands for GlusterFS
geo-replication, This mail is to fix the existing issues in these
command outputs. Let us know if we need any other columns which
helps users to get meaningful status.
Existing output
---------------
Status command output
MASTER NODE - Master node hostname/IP
MASTER VOL - Master volume name
MASTER BRICK - Master brick path
SLAVE - Slave host and Volume name(HOST::VOL format)
STATUS - Stable/Faulty/Active/Passive/Stopped/Not Started
CHECKPOINT STATUS - Details about Checkpoint completion
CRAWL STATUS - Hybrid/History/Changelog
Status detail -
MASTER NODE - Master node hostname/IP
MASTER VOL - Master volume name
MASTER BRICK - Master brick path
SLAVE - Slave host and Volume name(HOST::VOL format)
STATUS - Stable/Faulty/Active/Passive/Stopped/Not Started
CHECKPOINT STATUS - Details about Checkpoint completion
CRAWL STATUS - Hybrid/History/Changelog
FILES SYNCD - Number of Files Synced
FILES PENDING - Number of Files Pending
BYTES PENDING - Bytes pending
DELETES PENDING - Number of Deletes Pending
FILES SKIPPED - Number of Files skipped
Issues with existing status and status detail:
----------------------------------------------
1. Active/Passive and Stable/faulty status is mixed up - Same column
is used to show both active/passive status as well as Stable/faulty
status. If Active node goes faulty then by looking at the status it
is difficult to understand Active node is faulty or the passive one.
2. Info about last synced time, unless we set checkpoint it is
difficult to understand till what time data is synced to slave. For
example, if a admin want's to know all the files synced which are
created 15 mins ago, it is not possible without setting checkpoint.
3. Wrong values in metrics.
4. When multiple bricks present in same node. Status shows Faulty
when one of the worker is faulty in that node.
Changes:
--------
1. Active nodes will be prefixed with * to identify it is a active
node.(In xml output active tag will be introduced with values 0 or 1)
2. New column will show the last synced time, which minimizes the
use of checkpoint feature. Checkpoint status will be shown only in
status detail.
3. Checkpoint Status is removed, Separate Checkpoint command will be
added to gluster cli(We can introduce multiple Checkpoint feature
with this change)
4. Status values will be "Not
Started/Initializing/Started/Faulty/Stopped". Stable is changed to
"Started"
5. Slave User column will be introduced to show to which user
geo-rep session is established.(Useful in Non root geo-rep)
6. Bytes pending column will be removed. It is not possible to
identify the delta without simulating sync. For example, we are
using rsync to sync data from master to slave, If we need to know
how much data to be transferred then we have to run the rsync
command with --dry-run flag before running actual command. With
tar-ssh we have to stat all the files which are identified to be
synced to calculate the total bytes to be synced. Both are costly
operations which degrades the geo-rep performance.(In Future we can
include these columns)
7. Files pending, Synced, deletes pending are only session
information of the worker, these numbers will not match with the
number of files present in Filesystem. If worker restarts, counter
will reset to zero. When worker restarts, it logs previous session
stats before resetting it.
8. Files Skipped is persistent status across sessions, Shows exact
count of number of files skipped(Can get list of GFIDs skipped from
log file)
9. "Deletes Pending" column can be removed?
Is there any way to know if there are errors syncing any of the
files? Which column would that reflect in?
"Skipped" Column shows number of files failed to sync to Slave.
Is the last synced time - the least of the synced time across the nodes?
Status output will have one entry for each brick, so we are planning
to display last synced time from that brick.
Example output
MASTER NODE MASTER VOL MASTER BRICK SLAVE USER
SLAVE STATUS LAST SYNCED CRAWL
----------------------------------------------------------------------------------------------------------------
* fedoravm1 gvm /gfs/b1 root fedoravm3::gvs
Started 2014-05-10 03:07 pm Changelog
fedoravm2 gvm /gfs/b2 root fedoravm4::gvs
Started 2014-05-10 03:07 pm Changelog
New Status columns
ACTIVE_PASSIVE - * if Active else none.
MASTER NODE - Master node hostname/IP
MASTER VOL - Master volume name
MASTER BRICK - Master brick path
SLAVE USER - Slave user to which geo-rep is established.
SLAVE - Slave host and Volume name(HOST::VOL format)
STATUS - Stable/Faulty/Active/Passive/Stopped/Not Started
LAST SYNCED - Last synced time(Based on stime xattr)
CHECKPOINT STATUS - Details about Checkpoint completion
CRAWL STATUS - Hybrid/History/Changelog
FILES SYNCD - Number of Files Synced
FILES PENDING - Number of Files Pending
DELETES PENDING- Number of Deletes Pending
FILES SKIPPED - Number of Files skipped
XML output
active
master_node
master_node_uuid
master_brick
slave_user
slave
status
last_synced
crawl_status
files_syncd
files_pending
deletes_pending
files_skipped
Checkpoints
===========
New set of Gluster CLI commands will be introduced for Checkpoints.
gluster volume geo-replication <VOLNAME> <SLAVEHOST>::<SLAVEVOL>
checkpoint create <NAME> <DATE>
gluster volume geo-replication <VOLNAME> <SLAVEHOST>::<SLAVEVOL>
checkpoint delete <NAME>
gluster volume geo-replication <VOLNAME> <SLAVEHOST>::<SLAVEVOL>
checkpoint delete all
gluster volume geo-replication <VOLNAME> <SLAVEHOST>::<SLAVEVOL>
checkpoint status [<NAME>]
gluster volume geo-replication <VOLNAME> checkpoint status # For
all geo-rep sessions for that volume
gluster volume geo-replication checkpoint status # For all
geo-rep sessions for all volumes
Checkpoint Status:
SESSION NAME Completed Checkpoint
Time Completion Time
-----------------------------------------------------------------------------------------
gvm->root@fedoravm3::gvs Chk1 Yes 2014-11-30 11:30 pm
2014-12-01 02:30 pm
gvm->root@fedoravm3::gvs Chk2 No 2014-12-01 10:00 pm N/A
Can the time information have the timezone information as well? Or is
this UTC time?
(Same comment for last synced time)
Sure. Will have UTC time in Status output.
XML output:
session
master_uuid
name
completed
checkpoint_time
completion_time
--
regards
Aravinda
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