>>> "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.



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