Hi Guys, @Jonas thanks for sharing the link. I was just using default config which cames with mariadb 10..4 plus i increased cache size to 6GB, so that's the only option which is in the file: plugin-load-add=ha_rocksdb.so rocksdb_block_cache_size=61784 Basically i have just started trying it, so not very familiar with it and for my tests i just waited for all the background tasks for rocks to end so the server load is 0. No bloom filter... just simple SELECT sum(x) from y SELECT sum(x) from y WHERE index in Z then did 2 same queries to make sure all blocks are in the cache on some 100 million rows table. Basically what surprised me the most is that innodb was able to do around 180mb/s reads on this vm and it wasn't putting load on IO (1-2% WA on samsung 850 PRO), with rocks i had around 20mb/s and over 50% cpu time spent in i/o wait, so maybe i'll try debian 10 and totally fresh install. Might be that something is "broken" on debian9... @ Reinis ah really bad news, hopefully it won't be removed soon, it is so great I was actually hoping for it to become new innodb especially that its characteristics seems to be much more in tune with new hardware (many cpu cores, a lot of ram, ssd storage) than innodb and internally it seems to be "better b tree" so it's similar as well. Can you tell quickly why you were not able to use rocks? Thanks again! Dnia 12 września 2019 15:09 Jonas Krauss <jkraus...@gmail.com> napisał(a): Hello, how did you configure myrocks/rocksdb? Have you set up bloom filters? Maybe you could post your rocksdb options from the my.cnf in use here. This link was helpful to me when setting up myrocks: smalldatum.blogspot.com smalldatum.blogspot.com Regards Jonas Am Do., 12. Sept. 2019 um 14:44 Uhr schrieb jocelyn fournier < jocelyn.fourn...@gmail.com >: Hi! It seems MariaDB is dropping TokuDB in 10.5. See jira.mariadb.org jira.mariadb.org BR, Jocelyn Fournier > Le 12 sept. 2019 à 14:31, pslawek83 < pslawe...@o2.pl > a écrit : > > Hi Everyone, i got recently interested in rocks and have a couple of questions if anyone else is doing/done some migrations to this engine: > > 1. Noticed that compared to toku - I/O overhead for range SELECT's with cold caches is much higher, especially on vmware I/O utilization (WAit) goes over 50% of available CPU on standard cfq scheduler and 4 cores. Changing it to noop helps and utilization drops around tenfold to 5-10%. It doesn't matter if we're doing full table scan or range scan with index. Basically i thought for LSM lists there'll be almost no IOPs and I/O utilization will be non-existing because all you need to do is reading a long, continuous block on disk (we're using SSDs). Any reason for that or am i doing something incorrectly? (default config + 6gb rocks key cache) Any reason it's working so badly with cfq and much better with noop? > > 2. Now with keys 100% cached - rocks is still around 2-3 times slower than toku for range scans, and even considerably slower than innodb. From what i understand keycache for rocks stores uncompressed keys, so is there some performance issue eg. with copying data from global keycache to local storage and is it going to be fixed or that's something related to how rocks works internally and there's no way of making it work better in the future? > > 3. In general it was a huge surprise that toku which is (at least it seems) so complicated to implement, and is based on very complex variation of b tree is having so much better read performance and so much better i/o characteristics... than "simple" (from what i understand) sorted list, which could be probably just read in bulk like a simple log file... > > 4. I found some info that having rocks databases which are over 100gb in size is not recommended (and it seems this is tiny... we were able to work with myisam tables which were close to 2TB). Also merging data could make the DB to end up being twice as big for some time. Are there any plans of implementing one-file-per-table like for inno? > > 5. What's the future of toku? I understand that percona is considering dropping it, will you take developement if that will happen or are you going to obsolete it and focus on rocks? From what i saw it seems that rocks and toku have totally different characteristics. So rocks is decent for point-reads (seems faster than toku when number of row reads is low)... and it seems to require less memory than toku, but for range scans it isn't going nowhere close. So both engines may have completely different use cases (eg. toku is great for long running statistical queries and servers with a lot of memory) > > Thanks > ______________________________ > Mailing list: launchpad.net launchpad.net > Post to : maria-discuss@lists.launchpad. > Unsubscribe : launchpad.net launchpad.net > More help : help.launchpad.net help.launchpad.net ______________________________ Mailing list: launchpad.net launchpad.net Post to : maria-discuss@lists.launchpad. Unsubscribe : launchpad.net launchpad.net More help : help.launchpad.net help.launchpad.net
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