[COUCHDB-3184] couch_mrview_compactor:recompact/1 does not handle errors in spawned process

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Component/s: Database Core
• Assignee: Unassigned
• Reporter: Jay Doane
• Created: 07/Oct/16 16:44
• Updated: 20/Oct/16 17:12
• Resolved: 20/Oct/16 17:12

Description

The recompact function receive block only matches on tuples of the form

{'DOWN', Ref, _, _, {updated, Pid, State2}}

see: https://github.com/apache/couchdb-couch-mrview/blob/master/src/couch_mrview_compactor.erl#L156

but errors in the spawned process running couch_index_updater:update can return different forms, as shown in these processes captured by a user below. This results in the spawning process blocking forever in the receive.

([e-mail])1> process_info(pid(0,24597,7370)).
[{current_function,{couch_mrview_compactor,recompact,1}},
{initial_call,{erlang,apply,2}},
{status,waiting},
{message_queue_len,1},
{messages,[{'DOWN',#Ref<0.0.689040.41604>,process,
                    <0.9551.7382>,
                    {timeout,{gen_server,call,
                                        [couch_proc_manager,{get_proc,<<"javascript">>},5000]}}}]},
{links,[<0.14960.3332>,<0.4951.7370>]},
{dictionary,[{io_priority,{view_compact,<<"shards/80000000-9fffffff/default/master_party_db_perf.146124"...>>,
                                        <<"_design/sourcePrimaryKey_V">>}},
              {task_status_props,[{changes_done,12044429},
                                  {database,<<"shards/80000000-9fffffff/default/master_party_db"...>>},
                                  {design_document,<<"_design/sourcePrimaryKey_V">>},
                                  {phase,view},
                                  {progress,79},
                                  {started_on,1471048118},
                                  {total_changes,15182867},
                                  {type,view_compaction},
                                  {updated_on,1471048883},
                                  {view,0}]},
              {task_status_update,{{0,0,0},0}}]},
{trap_exit,false},
{error_handler,error_handler},
{priority,normal},
{group_leader,<0.237.0>},
{total_heap_size,954562},
{heap_size,121536},
{stack_size,15},
{reductions,354812127},
{garbage_collection,[{min_bin_vheap_size,46422},
                      {min_heap_size,233},
                      {fullsweep_after,65535},
                      {minor_gcs,9}]},
{suspending,[]}]


([e-mail])1> process_info(pid(0,182,3858)).
[{current_function,{couch_mrview_compactor,recompact,1}},
{initial_call,{erlang,apply,2}},
{status,waiting},
{message_queue_len,1},
{messages,[{'DOWN',#Ref<0.0.661774.27928>,process,
                    <0.17557.3858>,
                    {{nocatch,{os_process_error,"OS process timed out."}},
                    [{couch_os_process,prompt,2,
                                        [{file,"src/couch_os_process.erl"},{line,59}]},
                      {couch_query_servers,map_doc_raw,2,
                                          [{file,"src/couch_query_servers.erl"},{line,84}]},
                      {couch_mrview_updater,'-map_docs/2-fun-0-',3,
                                            [{file,"src/couch_mrview_updater.erl"},{line,146}]},
                      {lists,foldl,3,[{file,"lists.erl"},{line,1261}]},
                      {couch_mrview_updater,map_docs,2,
                                            [{file,"src/couch_mrview_updater.erl"},{line,153}]}]}}]},
{links,[<0.31690.3859>,<0.32697.3856>]},
{dictionary,[{io_priority,{view_compact,<<"shards/40000000-5fffffff/default/master_party_db.1463838377">>,
                                        <<"_design/sourcePartyIdentifier_V">>}},
              {task_status_props,[{changes_done,7905},
                                  {database,<<"shards/40000000-5fffffff/default/master_party_db"...>>},
                                  {design_document,<<"_design/sourcePartyIdentifier_V">>},
                                  {phase,view},
                                  {progress,0},
                                  {started_on,1471298853},
                                  {total_changes,6261085},
                                  {type,view_compaction},
                                  {updated_on,1471298856},
                                  {view,0}]},
              {task_status_update,{{0,0,0},0}}]},
{trap_exit,false},
{error_handler,error_handler},
{priority,normal},
{group_leader,<0.218.0>},
{total_heap_size,364609},
{heap_size,46422},
{stack_size,15},
{reductions,230416},
{garbage_collection,[{min_bin_vheap_size,46422},
                      {min_heap_size,233},
                      {fullsweep_after,65535},
                      {minor_gcs,3}]},
{suspending,[]}]

Issue Links

• links to: GitHub Pull Request #58