On Tue, Mar 13, 2018 at 12:58 PM, Pranith Kumar Karampuri < pkara...@redhat.com> wrote:
> > > On Mon, Mar 12, 2018 at 6:23 PM, Ondrej Valousek < > ondrej.valou...@s3group.com> wrote: > >> Hi, >> >> Gluster will never perform well for small files. >> >> I believe there is nothing you can do with this. >> > > It is bad compared to a disk filesystem but I believe it is much closer to > NFS now. > > Andreas, > Looking at your workload, I am suspecting there to be lot of LOOKUPs > which reduce performance. Is it possible to do the following? > > # gluster volume profile <volname> info incremental > #execute your workload > # gluster volume profile <volname> info incremental > > /path/to/file/that/you/need/to/send/us > > If the last line in there is LOOKUP, mostly we need to enable nl-cache > feature and see how it performs. > Please attach this as extra information along with what Nitya asked in the previous mail. > > >> Ondrej >> >> >> >> *From:* gluster-users-boun...@gluster.org [mailto:gluster-users-bounces@ >> gluster.org] *On Behalf Of *Andreas Ericsson >> *Sent:* Monday, March 12, 2018 1:47 PM >> *To:* Gluster-users@gluster.org >> *Subject:* [Gluster-users] Expected performance for WORM scenario >> >> >> >> Heya fellas. >> >> >> >> I've been struggling quite a lot to get glusterfs to perform even >> halfdecently with a write-intensive workload. Testnumbers are from gluster >> 3.10.7. >> >> >> >> We store a bunch of small files in a doubly-tiered sha1 hash fanout >> directory structure. The directories themselves aren't overly full. Most of >> the data we write to gluster is "write once, read probably never", so 99% >> of all operations are of the write variety. >> >> >> >> The network between servers is sound. 10gb network cards run over a 10gb >> (doh) switch. iperf reports 9.86Gbit/sec. ping reports a latency of 0.1 - >> 0.2 ms. There is no firewall, no packet inspection and no nothing between >> the servers, and the 10gb switch is the only path between the two machines, >> so traffic isn't going over some 2mbit wifi by accident. >> >> >> >> Our main storage has always been really slow (write speed of roughly >> 1.5MiB/s), but I had long attributed that to the extremely slow disks we >> use to back it, so now that we're expanding I set up a new gluster cluster >> with state of the art NVMe SSD drives to boost performance. However, >> performance only hopped up to around 2.1MiB/s. Perplexed, I tried it first >> with a 3-node cluster using 2GB ramdrives, which got me up to 2.4MiB/s. My >> last resort was to use a single node running on ramdisk, just to 100% >> exclude any network shenanigans, but the write performance stayed at an >> absolutely abysmal 3MiB/s. >> >> >> >> Writing straight to (the same) ramdisk gives me "normal" ramdisk speed (I >> don't actually remember the numbers, but my test that took 2 minutes with >> gluster completed before I had time to blink). Writing straight to the >> backing SSD drives gives me a throughput of 96MiB/sec. >> >> >> >> The test itself writes 8494 files that I simply took randomly from our >> production environment, comprising a total of 63.4MiB (so average file size >> is just under 8k. Most are actually close to 4k though, with the occasional >> 2-or-so MB file in there. >> >> >> >> I have googled and read a *lot* of performance-tuning guides, but the >> 3MiB/sec on single-node ramdisk seems to be far beyond the crippling one >> can cause by misconfiguration of a single system. >> >> >> >> With this in mind; What sort of write performance can one reasonably hope >> to get with gluster? Assume a 3-node cluster running on top of (small) >> ramdisks on a fast and stable network. Is it just a bad fit for our >> workload? >> >> >> >> /Andreas >> >> ----- >> >> The information contained in this e-mail and in any attachments is >> confidential and is designated solely for the attention of the intended >> recipient(s). If you are not an intended recipient, you must not use, >> disclose, copy, distribute or retain this e-mail or any part thereof. If you >> have received this e-mail in error, please notify the sender by return >> e-mail and delete all copies of this e-mail from your computer system(s). >> Please direct any additional queries to: communicati...@s3group.com. Thank >> You. Silicon and Software Systems Limited (S3 Group). Registered in Ireland >> no. 378073. Registered Office: South County Business Park, Leopardstown, >> Dublin 18. >> >> >> _______________________________________________ >> Gluster-users mailing list >> Gluster-users@gluster.org >> http://lists.gluster.org/mailman/listinfo/gluster-users >> > > > > -- > Pranith > -- Pranith
_______________________________________________ Gluster-users mailing list Gluster-users@gluster.org http://lists.gluster.org/mailman/listinfo/gluster-users
