Use fabric to get design docs in the compaction daemonfix-view-compaction

Previously the compaction daemon looked for design docs in each shard file.
This worked well for versions < 2.x, however, for clustered databases design
documents will only be found in their respective shards based on the document
id hashing algorithm. This meant that in a default setup of Q=8 only the views
of one shard range, where the _design document lives, would be compacted.

The fix for this issue is to use fabric to retrive all the design documents for
clustered database.

Issue #1579

1 files changed, 30 insertions, 0 deletions

diff --git a/src/couch/src/couch_compaction_daemon.erl b/src/couch/src/couch_compaction_daemon.erl
index 1a535dba7..608ea1908 100644
--- a/src/couch/src/couch_compaction_daemon.erl
+++ b/src/couch/src/couch_compaction_daemon.erl
@@ -239,6 +239,36 @@ maybe_compact_views(DbName, [DDocName | Rest], Config) ->
 
 
 db_ddoc_names(Db) ->
+    DbName = couch_db:name(Db),
+    ClusteredDbName = mem3:dbname(DbName),
+    case ClusteredDbName == DbName of
+        true ->
+            db_local_ddoc_names(Db);
+        false ->
+            db_cluster_ddoc_names(ClusteredDbName)
+    end.
+
+
+db_cluster_ddoc_names(ClusteredDbName) ->
+    try
+        case fabric:design_docs(ClusteredDbName) of
+            {ok, DDocs} ->
+                lists:map(fun({Props}) ->
+                    DocId = proplists:get_value(<<"_id">>, Props),
+                    <<"_design/", GroupName/binary>> = DocId,
+                    GroupName
+                end, DDocs);
+            Error ->
+                ErrMsg = "Could not get design docs for ~p error:~p",
+                couch_log:error(ErrMsg, [ClusteredDbName, Error]),
+                []
+        end
+    catch error:database_does_not_exist ->
+        []
+    end.
+
+
+db_local_ddoc_names(Db) ->
     FoldFun = fun ddoc_name/2,
     Opts = [{start_key, <<"_design/">>}],
     {ok, DDocNames} = couch_db:fold_docs(Db, FoldFun, [], Opts),