OUD12c - Unreleased Connections between OUD Proxy Instances and Backend Directories with "result: 51" (Doc ID 3038680.1)

Last updated on SEPTEMBER 18, 2024

Applies to:

Symptoms

OUD proxy becomes unresponsive and a bunch of threads are hung waiting for a backend LDAP connection. The OUD proxy backend LDAP connection pool is filling up. The pool starts at minimum number of connections configured (default 10) and over time grows up to the maximum of number of connections configured (default 1000).

We can see this by viewing the LDAP Server monitoring:

{OUD_INSTANCE}/bin/ldapsearch -T -h {HOSTNAME} -p {PORT_ADMIN}-D "cn={DS_ADMIN}" -j /tmp/pwd.txt --useSSL --trustAll -b "cn=proxy_extension_oud,cn=LDAP Servers,cn=monitor" "objectclass=*" ds-mon-secured-connections-count

This number reflected by the ds-mon-secured-connections-count may not be correct. The connects rarely free up and the number rarely decreases. It just increases until it hits the maximum of number of connections configured (default 1000). Once it hits the maximum the OUD proxy instance hangs waiting for a connection. This will hang indefinitely until the OUD proxy instance is restarted.

If we look at the connections on the server with the netstat command you will rarely see more than 10 to 15 connections to the backend LDAP. The number of connections is consistent, but yet the number reflected in the ds-mon-secured-connections-count continues to rise over time.

When max number of connections are reached, proxy refuses any further connections and generate LDAP error 51.

Changes

Cause

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