[couchdb] branch prototype/fdb-layer updated: Handle transaction and future timeouts in couch_jobs notifiers

[va...@apache.org]

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vatamane pushed a commit to branch prototype/fdb-layer
in repository https://gitbox.apache.org/repos/asf/couchdb.git


The following commit(s) were added to refs/heads/prototype/fdb-layer by this push:
     new b17bc49  Handle transaction and future timeouts in couch_jobs notifiers
b17bc49 is described below

commit b17bc49aac9e20696ca530bb09e21cefa4e4d6d1
Author: Nick Vatamaniuc <va...@apache.org>
AuthorDate: Wed Jun 10 17:22:36 2020 -0400

    Handle transaction and future timeouts in couch_jobs notifiers
    
    In an overload scenario do not let notifiers crash and lose their subscribers,
    instead make them more robust and let them retry on future or transaction
    timeouts.
---
 src/couch_jobs/src/couch_jobs_notifier.erl | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/src/couch_jobs/src/couch_jobs_notifier.erl b/src/couch_jobs/src/couch_jobs_notifier.erl
index 1c554a0..ff4492b 100644
--- a/src/couch_jobs/src/couch_jobs_notifier.erl
+++ b/src/couch_jobs/src/couch_jobs_notifier.erl
@@ -115,7 +115,7 @@ handle_cast(Msg, St) ->
 
 handle_info({type_updated, VS}, St) ->
     VSMax = flush_type_updated_messages(VS),
-    {noreply, notify_subscribers(VSMax, St)};
+    {noreply, try_notify_subscribers(VSMax, St)};
 
 handle_info({Ref, ready}, St) when is_reference(Ref) ->
     % Don't crash out couch_jobs_server and the whole application would need to
@@ -228,6 +228,15 @@ get_active_since(#st{jtx = JTx, type = Type, subs = Subs}, VS) ->
     end, maps:with(maps:keys(Subs), AllUpdated)).
 
 
+try_notify_subscribers(ActiveVS, #st{} = St) ->
+    try
+        notify_subscribers(ActiveVS, St)
+    catch
+        error:{timeout, _} -> try_notify_subscribers(ActiveVS, St);
+        error:{erlfdb_error, 1031} -> try_notify_subscribers(ActiveVS, St)
+    end.
+
+
 notify_subscribers(_, #st{subs = Subs} = St) when map_size(Subs) =:= 0 ->
     St;