[couchdb] branch handle-replication-process-restart-better updated (37a083e -> 89dc385)

[va...@apache.org]

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vatamane pushed a change to branch handle-replication-process-restart-better
in repository https://gitbox.apache.org/repos/asf/couchdb.git.


 discard 37a083e  Do not mark replication jobs as failed if doc processor crashes
     new 89dc385  Do not mark replication jobs as failed if doc processor crashes

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Summary of changes:
 src/couch_replicator/src/couch_replicator_doc_processor.erl | 1 -
 1 file changed, 1 deletion(-)

[couchdb] 01/01: Do not mark replication jobs as failed if doc processor crashes

[va...@apache.org]

This is an automated email from the ASF dual-hosted git repository.

vatamane pushed a commit to branch handle-replication-process-restart-better
in repository https://gitbox.apache.org/repos/asf/couchdb.git

commit 89dc3852a1f1df4483dd1194dfa3561c16b0d4d3
Author: Nick Vatamaniuc <va...@apache.org>
AuthorDate: Fri Nov 1 13:46:44 2019 -0400

    Do not mark replication jobs as failed if doc processor crashes
    
    Previously if couch_replicator_doc_processor crashed, the job was marked as
    "failed". We now ignore that case. It's safe to do that since supervisor will
    restart it anyway, and it will rescan all the docs again. Most of all, we want
    to prevent the job becoming failed permanently and needing a manual
    intervention to restart it.
---
 .../src/couch_replicator_doc_processor.erl         | 29 +++++++++++++++++++---
 1 file changed, 25 insertions(+), 4 deletions(-)

diff --git a/src/couch_replicator/src/couch_replicator_doc_processor.erl b/src/couch_replicator/src/couch_replicator_doc_processor.erl
index 772037d..23cdeea 100644
--- a/src/couch_replicator/src/couch_replicator_doc_processor.erl
+++ b/src/couch_replicator/src/couch_replicator_doc_processor.erl
@@ -101,6 +101,9 @@ db_change(DbName, {ChangeProps} = Change, Server) ->
     try
         ok = process_change(DbName, Change)
     catch
+    exit:{Error, {gen_server, call, [?MODULE, _, _]}} ->
+        ErrMsg = "~p exited ~p while processing change from db ~p",
+        couch_log:error(ErrMsg, [?MODULE, Error, DbName]);
     _Tag:Error ->
         {RepProps} = get_json_value(doc, ChangeProps),
         DocId = get_json_value(<<"_id">>, RepProps),
@@ -611,6 +614,7 @@ cluster_membership_foldl(#rdoc{id = {DbName, DocId} = Id, rid = RepId}, nil) ->
 -include_lib("eunit/include/eunit.hrl").
 
 -define(DB, <<"db">>).
+-define(EXIT_DB, <<"exit_db">>).
 -define(DOC1, <<"doc1">>).
 -define(DOC2, <<"doc2">>).
 -define(R1, {"1", ""}).
@@ -625,6 +629,7 @@ doc_processor_test_() ->
         [
             t_bad_change(),
             t_regular_change(),
+            t_change_with_doc_processor_crash(),
             t_change_with_existing_job(),
             t_deleted_change(),
             t_triggered_change(),
@@ -658,6 +663,15 @@ t_regular_change() ->
     end).
 
 
+% Handle cases where doc processor exits or crashes while processing a change
+t_change_with_doc_processor_crash() ->
+    ?_test(begin
+        mock_existing_jobs_lookup([]),
+        ?assertEqual(acc, db_change(?EXIT_DB, change(), acc)),
+        ?assert(failed_state_not_updated())
+  end).
+
+
 % Regular change, parse to a #rep{} and then add job but there is already
 % a running job with same Id found.
 t_change_with_existing_job() ->
@@ -834,16 +848,19 @@ setup() ->
     meck:expect(couch_replicator_clustering, owner, 2, node()),
     meck:expect(couch_replicator_clustering, link_cluster_event_listener, 3,
         ok),
-    meck:expect(couch_replicator_doc_processor_worker, spawn_worker, 4, pid),
+    meck:expect(couch_replicator_doc_processor_worker, spawn_worker, fun
+        ({?EXIT_DB, _}, _, _, _) -> exit(kapow);
+        (_, _, _, _) -> pid
+    end),
     meck:expect(couch_replicator_scheduler, remove_job, 1, ok),
     meck:expect(couch_replicator_docs, remove_state_fields, 2, ok),
     meck:expect(couch_replicator_docs, update_failed, 3, ok),
     {ok, Pid} = start_link(),
+    unlink(Pid),
     Pid.
 
 
 teardown(Pid) ->
-    unlink(Pid),
     exit(Pid, kill),
     meck:unload().
 
@@ -871,10 +888,14 @@ did_not_spawn_worker() ->
 updated_doc_with_failed_state() ->
     1 == meck:num_calls(couch_replicator_docs, update_failed, '_').
 
+failed_state_not_updated() ->
+    0 == meck:num_calls(couch_replicator_docs, update_failed, '_').
 
 mock_existing_jobs_lookup(ExistingJobs) ->
-    meck:expect(couch_replicator_scheduler, find_jobs_by_doc,
-        fun(?DB, ?DOC1) -> ExistingJobs end).
+    meck:expect(couch_replicator_scheduler, find_jobs_by_doc, fun
+        (?EXIT_DB, ?DOC1) -> [];
+        (?DB, ?DOC1) -> ExistingJobs
+    end).
 
 
 test_rep(Id) ->