Thanks for your valuable answer about write cache! For object gateway, the performance is got by `swift-bench -t 64` which uses 64 threads concurrently. Will the radosgw and http overhead be so significant (94.5MB/s to 26MB/s for cluster1) when multiple threads are used? Thanks in advance! On Wed, Feb 5, 2020, 11:33 PM Janne Johansson <icepic.dz@xxxxxxxxx> wrote: > Den ons 5 feb. 2020 kl 16:19 skrev quexian da <daquexian566@xxxxxxxxx>: > >> Thanks for your valuable answer! >> Is the write cache specific to ceph? Could you please provide some links >> to the documentation about the write cache? Thanks! >> >> > It is all the possible caches used by ceph, by the device driver, the > filesystem (in filestore+xfs), the controllers (emulated or real) and the > harddisk electronics, ie anything between the benchmark software and the > spinning disk write head (or not so spinning on ssds). > > >> Do you have any idea about the slow oss speed? Is it normal that the >> write performance of object gateway is slower than that of rados cluster? >> Thanks in advance! >> >> > Object gateway (be it swift or S3) goes over something that looks like > http, so it will most certainly have longer turn around times and hence > slower speed for single streams. > You may possibly get over parts of that overhead by having many multiple > streams and counting the sum of the transfers, but there is no big surprise > that individual writes get slower if you have to pass via an external box > (the radosgw) using https instead of writing directly to the storage. > > -- > May the most significant bit of your life be positive. > _______________________________________________ ceph-users mailing list -- ceph-users@xxxxxxx To unsubscribe send an email to ceph-users-leave@xxxxxxx
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