SAP "sapstartsrv" process encounter "Too many open files" errors in SLE15 SP6 that uses SSSD

This document (000021660) is provided subject to the disclaimer at the end of this document.

Environment

SUSE Linux Enterprise Server 15 SP6

Situation

After upgrading to SLE15 SP6, some SAP "sapstartsrv" process started to encounter "Too many open files" errors after running for some time.
Example of SAP error messages in "sapstartsrv.log":

[Thr 140458087995072] ***LOG Q0I=> NiIAccept2: accept (24: Too many open files) [nixxi.cpp 3538]
[Thr 140458087995072] *** ERROR => NiIAccept2: SiAccept failed for hdl 11/sock 22

The "sapstartsrv" process has numerous Unix domain socket ("/var/lib/sss/pipes/nss") that are not closed, and it keeps growing until the limit is reached.

Resolution

This file descriptor leak bug is fixed in the sssd patch "SUSE-SLE-Module-Basesystem-15-SP6-2025-7" (version number 2.9.3-150600.3.15.1).

Cause

The "getpwnam()" or "getpwuid()" calls within a thread in a system that uses sssd would leak a file descriptor until the end of the program's runtime.
The bug fix ensures the file descriptor is closed when the thread exits.

Additional Information

All SLE15 SP6 systems using sssd version 2.9.3-150600.3.15.1 (and earlier versions) are affected by this bug.

Disclaimer

This Support Knowledgebase provides a valuable tool for SUSE customers and parties interested in our products and solutions to acquire information, ideas and learn from one another. Materials are provided for informational, personal or non-commercial use within your organization and are presented "AS IS" WITHOUT WARRANTY OF ANY KIND.