On the doc
Additional-identity-manager-directory-properties
It mentions tuning LDAP connection settings
LDAP connection parameters are system-level properties, and therefore, it is recommended that you apply them to the JAVA_OPTS variable using the -D command option:
But did not provide more detail on HOWTO
Identity Manager 14.5 Windows 2019 EAP 7.4
HowTo information
1) Stop IDM service
2) Modified the standalone.conf.bat under JBOSS_HOME/bin
Adding line
set "JAVA_OPTS=%JAVA_OPTS% -Dcom.sun.jndi.ldap.connect.timeout=600000 -Dcom.sun.jndi.ldap.connect.pool.maxsize=500 -Dcom.sun.jndi.ldap.connect.pool.prefsize=200"
3) Restart IDM