On Apr 16, 2012, at 1:50 PM, Rich Megginson wrote:
I would still like to know which parameters you set and the values
When I first tried this, the change log was set to unlimited, (the default), and the purge
delay was set to 7 days I think. I reduced the purge delay to about 15 minutes. and about
10 minutes for the change log entry age. These were changed using the console and then
the server was restarted. I'm not sure of this exactly because those settings were
deleted when I deleted the replication agreement and stopped the changelogging.
>>> The consumer has processed all updates and also seems to exhibit
overconsumption of memory.
>> Do you see any issue if you don't use replication at all? That is, is this
issue related to replication?
> Yes, I haven't seen it jump up all the way yet, but it is up to 13GB after only a
> This was without replication enabled.
> When I re-enabled replication just now to see if the excess entries would be
replicated to the consumer, I see that thousands of entries are being sent over during
consumer initialization. It just finished replicating and sent 7639 entries. There are
only about 800 valid entries. Searching from the base suffix for all available current DN
values on the master results in only "# numEntries: 855"
I wonder if they are tombstone entries? Are you doing ldapdelete operations at all?
Could be. Yes, the entries are deleted using ldapdelete over a file of DN values. I was
incorrect when I mentioned that I was using ldapmodify in this case.
I'm not very familiar with the concept of "tombstone" but I used dbscan to
look over the id2entry file, and it contains all 7639 entries that were being sent over.
If the tombstone issue is causing the server to hold onto duplicate entries, then maybe I
just have to run deletions in a different way...
> After restarting the master and doing another consumer
initialization, there seems to remain a record of these excess entries and the consumer is
being initialized with them even though the change log is currently empty at 16K.
Consumer initialization does not use the changelog - it reads the entries directly from
the database and sends them to the consumer.
> Perhaps there is a problem with the way I am deleting and adding entries and they are
being duplicated behind the scenes somehow??? I'm just using a db2ldif export of
those entries and running ldapadd over that file...
>>> Are there any pointers related to this?
>> Are you seeing https://fedorahosted.org/389/ticket/51
>> When you start to see memory growth, are you using all of your cache?
> I am not using MMR (pretty sure unless that came enabled by default), nor am I using
> The memory usage pushes well beyond the cache size.
The thing about ticket 51 (not sure if it is in the ticket, perhaps it is in the linked
bugzilla bug) is that the memory growth is only seen _if the entry cache is maxed out_.
That is, if you are able to keep the entry cache max size well above the actual amount of
data used, you do not see the memory growth. We have also run valgrind but have not seen
any "real" memory leaks. Note that entries stored in the entry cache will be
reported as "leaks" because we do not free the entry cache at shutdown. Our
best guess for the memory growth issues in ticket 51 is that either there is a very subtle
memory leak related to entry "churn" as entries are evicted and stored in the
entry cache, or the memory fragmentation that results from that churn.
Initially, the entry cache was set to 12G, far in excess of the database in its reduced
>>> If there is no information about this, is there a documentation page that
might instruct me in the correct way to attach valgrind to the ns-slapd process so I can
see if there is some kind of huge leak?
>> AFAIK you can't attach valgrind to a running process.
>> try this:
>> service dirsrv stop
>> ( . /etc/sysconfig/dirsrv ; . /etc/sysconfig/dirsrv-INSTANCENAME ; valgrind -q
--tool=memcheck --leak-check=yes --leak-resolution=high --num-callers=50
--log-file=/var/log/dirsrv/slapd-INSTANCENAME/valgrind.log /usr/sbin/ns-slapd -D
/etc/dirsrv/slapd-INSTANCENAME -i /var/run/dirsrv/slapd-INSTANCENAME.pid -w
/var/run/dirsrv/slapd-INSTANCENAME.startpid -d 0 ) &
>> valgrind will log to /var/log/dirsrv/slapd-INSTANCENAME/valgrind.log
>> Note that running your server with valgrind will really cripple the performance -
may be unusable in a production environment - you may also run afoul of selinux
>> valgrind will not report memory leaks until you shutdown the server (just kill
-15 <pid of ns-slapd or valgrind>)
> I'll give this a shot and see what happens.
> Looks like we already have some kind of handle to the situation since the excess
entries are already being reported by the entry caches.
? Not sure what you mean here.
This means that the server is creating and holding onto excess entries, and the server is
reporting this fact. This would be a different type of leak than lost memory where
valgrind would be needed to see.
> Thanks so much for your advices!