diff options
author | Raghavendra G <rgowdapp@redhat.com> | 2017-02-28 13:13:59 +0530 |
---|---|---|
committer | Raghavendra G <rgowdapp@redhat.com> | 2017-03-01 09:35:48 -0500 |
commit | 773f32caf190af4ee48818279b6e6d3c9f2ecc79 (patch) | |
tree | e94281239124bc9933934bbc162e4057ac555621 /rpc/rpc-lib/src/rpc-clnt.h | |
parent | 13201e55299b4229a4481d886b12fd34d76044ac (diff) |
rpc/clnt: remove locks while notifying CONNECT/DISCONNECT
Locking during notify was introduced as part of commit
aa22f24f5db7659387704998ae01520708869873 [1]. The fix was introduced
to fix out-of-order CONNECT/DISCONNECT events from rpc-clnt to parent
xlators [2]. However as part of handling DISCONNECT protocol/client
does unwind saved frames (with failure) waiting for responses. This
saved_frames_unwind can be a costly operation and hence ideally
shouldn't be included in the critical section of notifylock, as it
unnecessarily delays the reconnection to same brick. Also, its not a
good practise to pass control to other xlators holding a lock as it
can lead to deadlocks. So, this patch removes locking in rpc-clnt
while notifying parent xlators.
To fix [2], two changes are present in this patch:
* notify DISCONNECT before cleaning up rpc connection (same as commit
a6b63e11b7758cf1bfcb6798, patch [3]).
* protocol/client uses rpc_clnt_cleanup_and_start, which cleans up rpc
connection and does a start while handling a DISCONNECT event from
rpc. Note that patch [3] was reverted as rpc_clnt_start called in
quick_reconnect path of protocol/client didn't invoke connect on
transport as the connection was not cleaned up _yet_ (as cleanup was
moved post notification in rpc-clnt). This resulted in clients never
attempting connect to bricks.
Note that one of the neater ways to fix [2] (without using locks) is
to introduce generation numbers to map CONNECT and DISCONNECTS across
epochs and ignore DISCONNECT events if they don't belong to current
epoch. However, this approach is a bit complex to implement and
requires time. So, current patch is a hacky stop-gap fix till we come
up with a more cleaner solution.
[1] http://review.gluster.org/15916
[2] https://bugzilla.redhat.com/show_bug.cgi?id=1386626
[3] http://review.gluster.org/15681
Change-Id: I62daeee8bb1430004e28558f6eb133efd4ccf418
Signed-off-by: Raghavendra G <rgowdapp@redhat.com>
BUG: 1427012
Reviewed-on: https://review.gluster.org/16784
Smoke: Gluster Build System <jenkins@build.gluster.org>
Reviewed-by: Milind Changire <mchangir@redhat.com>
NetBSD-regression: NetBSD Build System <jenkins@build.gluster.org>
CentOS-regression: Gluster Build System <jenkins@build.gluster.org>
Diffstat (limited to 'rpc/rpc-lib/src/rpc-clnt.h')
-rw-r--r-- | rpc/rpc-lib/src/rpc-clnt.h | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/rpc/rpc-lib/src/rpc-clnt.h b/rpc/rpc-lib/src/rpc-clnt.h index 4d66498a0aa..b731ba2dfad 100644 --- a/rpc/rpc-lib/src/rpc-clnt.h +++ b/rpc/rpc-lib/src/rpc-clnt.h @@ -149,6 +149,7 @@ struct rpc_clnt_connection { int32_t ping_timeout; uint64_t pingcnt; uint64_t msgcnt; + uint64_t cleanup_gen; }; typedef struct rpc_clnt_connection rpc_clnt_connection_t; @@ -171,7 +172,6 @@ struct rpc_req { typedef struct rpc_clnt { pthread_mutex_t lock; - pthread_mutex_t notifylock; rpc_clnt_notify_t notifyfn; rpc_clnt_connection_t conn; void *mydata; @@ -198,6 +198,8 @@ struct rpc_clnt *rpc_clnt_new (dict_t *options, xlator_t *owner, int rpc_clnt_start (struct rpc_clnt *rpc); +int rpc_clnt_cleanup_and_start (struct rpc_clnt *rpc); + int rpc_clnt_register_notify (struct rpc_clnt *rpc, rpc_clnt_notify_t fn, void *mydata); |