[SAP] Fix race condition in NetApp REST client session handling#335
Open
hemna wants to merge 2 commits into
Open
[SAP] Fix race condition in NetApp REST client session handling#335hemna wants to merge 2 commits into
hemna wants to merge 2 commits into
Conversation
Create the clone on the template DS and later moves to target ds via svmotion post clone Change-Id: Icc4dda70f98498723c622913dfc383fb27b25da6
The RestNaServer.send_http_request() method was rebuilding self._session on every call via _build_session() without any locking or thread-local isolation. In an eventlet environment with concurrent greenthreads, this caused a race condition where one greenthread's session headers (including the critical X-Dot-SVM-Name vserver tunneling header) could be silently overwritten by another greenthread's _build_session() call before the HTTP request was actually sent. This manifested in production as the get_operational_lif_addresses() REST call intermittently returning LIFs for the wrong vserver (or an empty set), because the tunneling header was lost due to the race. The driver then logged 'Address not found for NFS share' for all configured shares, reported zero pools to the scheduler, and the backend became invisible to the volume controller's pool cache — permanently, since the cache has no TTL or retry logic. The fix eliminates the shared mutable state by making _build_session() return a new local Session object instead of storing it on self._session. Each concurrent REST call now gets its own isolated session with the correct headers, preventing any cross-greenthread contamination. This is the proper fix for the class of issues previously worked around in commit deebedf ('use zapi in _get_flexvol_to_pool_map'), which forced get_flexvol calls through the ZAPI fallback path to avoid this same REST client race condition. Change-Id: Ida5dbde04e4976b41d88fcd82c0573df7721cb0a
hemna
force-pushed
the
fix/rest-client-session-race-2025.1
branch
from
9105951 to
b541985
Compare
Scsabiii
approved these changes
May 12, 2026
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
2 participants
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Summary