Bug 1341184

+++ This bug was initially created as a clone of Bug #1340361 +++

Description of problem:

This was observed on one of user's production setup.

[raghu@unused 01610290]$ grep "cannot lookup the saved" <client-log>
[2016-02-15 22:40:02.575925] C [rpc-clnt.c:452:rpc_clnt_fill_request_info] <client-log>: cannot lookup the saved frame corresponding to xid (14161323)

Above is the log-message indicating that a reply from server couldn't lookup a saved-frame to unwind the response. The xid (0xd815ab) matches to one of the unaccounted call-bails. Similar msg was seen from other log.

As for the RCA for not able to lookup a saved frame for response, I saw in rpc-clnt:

1. Submit the request to transport for transmission to brick.
2. Save the frame for future reference while processing reply.

Now, if we get a response between 1 and 2 (before we were able to save the frame), we would be saving the frame of a request whose reply is already received. This can result in call-bail.


Version-Release number of selected component (if applicable):
Zero day bug, present in all releases

How reproducible:
Racy. Not consistent

Steps to Reproduce:
1.
2.
3.

Actual results:
A reply didn't have an associated saved-frame in rpc-clnt layer.

Expected results:
A reply should always have a saved-frame in rpc-clnt layer.


Additional info:

--- Additional comment from Vijay Bellur on 2016-05-27 09:36:29 CEST ---

REVIEW: http://review.gluster.org/14547 (rpc-clnt: save the frame before submitting request to transport) posted (#1) for review on master by Raghavendra G (rgowdapp)