Hi, > Op 27 jul. 2022 om 12:37 heeft Cédric Counotte <cedric.couno...@1check.com> > het volgende geschreven: > > > Thanks for your reply ! > > If the server does an SST, the problem is way more dramatic than when it does > an IST. > > This morning one server crashed and upon restarting it did an SST instead of > an IST, and the issue was horrible. > Even before being available, it blocked the donor for 15 minutes with > something like those: > > 2022-07-27 12:02:42 7 [Note] WSREP: Processing event queue:... 20.9% ( > 496/2376 events) complete.
Does the issue occur while these messages are logged? > For a while it got even slower to process the queue than the queue was > increasing. > > The same server crashed again so I started another one and it did an SST, but > the problem was not as dramatic, however the processing even queue lasted 5 > minutes and blocked the donor completed for that time. In very rare occasions > the SST is not causing such issues, but very rare (twice in 6 months and 2 or > 3 dozen of issue occurrences) and I didn’t change any settings since!? Very > confusing. > > When servers do an SST, I usually kill the CHECK TABLE FOR UPGRADE that > occurs as it appears to slow things down even more. > > Noticeably this morning I had 3 servers running, one went haywire, and caused > another one to go down! Ended-up with a single server I had to restart caused > it would complain about not being wsrep ready. > > > It’s been a very bad day today as those 4 servers are in production and we > received dozens of calls from our customers. Again, I’d focus on cause. The effect is clear. > Now I’m back with 2 servers and will wait tonight to restart the 2 others > because of that issue. > > IMO it’s a bug as in very rare occasions it starts smoothly. But still I > found galera to be unreliable and my company is asking me to install a more > reliable solution ASAP or we will loose customers! So any help would be much > appreciated. Whether something’s a bug is not an opinion. > I’m thinking of using 3 servers with replication instead, keeping load > balancing using source Ips, but I’m worried that this might be less reliable. > We have 2 spare servers in another location, synched with replication but it > happened too often that upon a server crash the replication would no longer > start and had to be entirely restarted which shows as not being even less > reliable. > > Sorry for the long story, but I’m no Galera expert Then you could indeed wonder if your company should be using Galera … > and I’m having lots of issues I can’t find any info or solution about. > > This is another issue I’m facing with replication, while it seems to be > caused by galera cluster: https://jira.mariadb.org/browse/MDEV-29132 > > > > De : William Edwards <wedwa...@cyberfusion.nl> > Envoyé : mercredi 27 juillet 2022 11:58 > À : Cédric Counotte <cedric.couno...@1check.com> > Cc : maria-discuss@lists.launchpad.net > Objet : Re: [Maria-discuss] MariaDB server horribly slow on start > > > Op 27 jul. 2022 om 11:46 heeft Cédric Counotte <cedric.couno...@1check.com> > het volgende geschreven: > > > Hello all. I hope I’m at the right place to ask this question. > I opened a bug here: https://jira.mariadb.org/browse/MDEV-28969, however I > was told to use this mailing list. > > We have 4 MariaDB servers in a Galera Cluster and it happens that a server > has to be restarted (be it for a crash which I have to open a bug for) or > maintenance. > > When that happens, the restarted server is causing huge slow down on the > whole cluster, and it lasts for 10 to 30 minutes at the very least! > > And by huge, I mean huge, we end up with 500 to 800 pending queries on all > servers as you can see on attached screenshots > I’ve attached the configuration of any server for reference in case this is > the source of the issue. > > Any way to solve this would be greatly appreciated. > > You seem to be focusing on effect. What is the cause? SST? > > > > Regards, > 3C. > > _______________________________________________ > Mailing list: https://launchpad.net/~maria-discuss > Post to : maria-discuss@lists.launchpad.net > Unsubscribe : https://launchpad.net/~maria-discuss > More help : https://help.launchpad.net/ListHelp
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