(ITS#8907) Memory leak on mass adding users to ldap

[nowhereman@nowhereman.ru]

Full_Name: Alexey Karpov
Version: 2.4.44
OS: RHEL 7.5
URL: ftp://ftp.openldap.org/incoming/
Submission from: (NULL) (87.245.195.105)


We have two OpenLDAP servers version 2.4.44, running on RHEL 7.5, replicated in
mirror mode and working as active-standby. OpenLDAP works as userstore for WSO2
Identity Server. Servers configured with tls security and valid certificates.
All requests come to first server (ldap1), second server (ldap2) working as
reserve.

When we start batch adding users (about 3-5 inserts per second, mixed with
queries and changing values), we observe a memory leak on server ldap1,
load-dependent, up to gigabyte per minute, and the lag in sync between servers.
If we stop server ldap2, leaking stops and server ldap1 working properly. Memory
is not freeing until server is restarted.

Also we try this setup with version 2.4.44 on Centos 7 and custom builded
version 2.4.46 on Centos 7. Results are the same - on batch adding users,
server, receiving requests has memory leak and leaking stops when second server
stopped.