>>> "Paul B. Henson" <hen...@acm.org> schrieb am 22.05.2022 um 04:51 in >>> Nachricht <5d343067-aef3-b499-63e3-996f3d680...@acm.org>: > On 5/11/2022 3:48 AM, Soisik Froger wrote: > >> Are this performance issues an expected side-effect of switching to >> dynlist - as the memberOf attributes are now dynamically calculated >> while the memberOf overlay used to writes these attributes - or > > I am also having ongoing sporadic issues with memberOf performance using > the new dynlist overlay. Initially, randomly a server would get into a > state where any query requesting the memberOf attribute would take in > excess of 30 seconds, whereas normally it would only take a fraction of > a second. The symptoms were the same, free memory, no swapping, but > insanely high read IO load.
I'm wondering: If you'd make a core dump when the issue happens, how big would such a core dump be with MDB? I'm afraid it would be insanely large, containing the whole database. Am I wrong? > > I cranked up the memory, which not did resolve the issue, but did help, > it doesn't happen nearly as often. But still, every now and again, a > server demonstrates a high read IO rate and severely degraded memberOf > query performance. At this point, I just have a monitoring check that > alerts on slow query performance and high read I/O and go restart them > when it happens, as the additional memory made the issue go from a > couple of times a week to every month or three. > > I did notice now that when the issue occurs the box with the slow > queries does have less memory available then when it is working > normally, but still a good gigabyte of free memory not being used. > > Even when the systems don't completely blow up, there are occasional > slower than normal queries. Typically the test query I am doing > literally takes fractions of a second: > > May 21 19:47:22 ldap-01 slapd[1223]: conn=849157 op=1 SEARCH RESULT > tag=101 err=0 qtime=0.000015 etime=0.198042 nentries=1 text= > > Every now and again for no discernible reason it might take 5 to 10 seconds.
