You are viewing a plain text version of this content. The canonical link for it is here.
Posted to notifications@couchdb.apache.org by "Mike Wallace (JIRA)" <ji...@apache.org> on 2015/09/09 18:52:45 UTC
[jira] [Commented] (COUCHDB-2804) The fast_view optimisation for
view-filtered changes feeds is not cluster-aware
[ https://issues.apache.org/jira/browse/COUCHDB-2804?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14737180#comment-14737180 ]
Mike Wallace commented on COUCHDB-2804:
---------------------------------------
In case anyone is interested, I did some (very handwavy) testing against the admin port to see how much of a speedup the fast_view optimisation gives us - I was typically getting results along these lines:
{code}
Raw changes: 1.702s
Filtered changes: 53.113s
Filtered-by-view changes: 57.041s
Fast-view changes: 9.500s
{code}
So it's certainly a valuable speed up.
(usual disclaimers apply - these figures were *not* obtained using science)
> The fast_view optimisation for view-filtered changes feeds is not cluster-aware
> -------------------------------------------------------------------------------
>
> Key: COUCHDB-2804
> URL: https://issues.apache.org/jira/browse/COUCHDB-2804
> Project: CouchDB
> Issue Type: Bug
> Security Level: public(Regular issues)
> Components: Database Core
> Affects Versions: 2.0.0
> Reporter: Mike Wallace
>
> The view changes functionality (the most up-to-date documentation I am aware of being here: https://github.com/rcouch/rcouch/wiki/View-Changes) needs some work to make the fast_view optimisation work via the clustered interface.
> This has been tested using the following script: https://gist.github.com/mikewallace1979/1f53f186e48bb888c256#file-test_fast_view-sh
> Running it against the admin port on 15986 produces a successful response [1] although people with an eye for detail will notice a secondary bug where the first change isn't included.
> Running it against the clustered port on 15984 produces a stack trace [2]:
> {code}
> {"error":"error","reason":"{function_clause,nil,\n [{couch_changes,filter,\n [{db,<26600.3277.0>,nil,<<\"1441816974537529\">>,<26600.3259.0>,\n #Ref<26600.0.0.19015>,\n {db_header,6,1,0,\n {4310,{1,0,{size_info,68,105}},96},\n {4406,1,93},\n {21426,[],1273},\n 0,nil,nil,1000,<<\"585e0d4edddc04b8423fee965a730e4c\">>,\n [{'node2@127.0.0.1',0}],\n 0},\n 1,\n {btree,<26600.3259.0>,\n {4310,{1,0,{size_info,68,105}},96},\n #Fun<couch_db_updater.btree_by_id_split.1>,\n #Fun<couch_db_updater.btree_by_id_join.2>,undefined,\n #Fun<couch_db_updater.btree_by_id_reduce.2>,snappy},\n {btree,<26600.3259.0>,\n {4406,1,93},\n #Fun<couch_db_updater.btree_by_seq_split.1>,\n #Fun<couch_db_updater.btree_by_seq_join.2>,undefined,\n #Fun<couch_db_updater.btree_by_seq_reduce.2>,snappy},\n {btree,<26600.3259.0>,\n {21426,[],1273},\n undefined,undefined,undefined,nil,snappy},\n 1,<<\"shards/c0000000-dfffffff/test_db.1441816974\">>,\n \"/Users/mikewallace/src/asf/couchdb/dev/lib/node2/data/shards/c0000000-dfffffff/test_db.1441816974.couch\",\n undefined,[],nil,\n {user_ctx,null,[],undefined},\n nil,1000,\n [before_header,after_header,on_file_open],\n [create],\n snappy,nil,nil},\n {doc_info,<<\"doge\">>,1,\n [{rev_info,\n {1,\n <<174,50,232,100,203,90,27,198,130,81,79,221,160,216,74,\n 128>>},\n 1,false,4242}]},\n {fast_view,main_only,\n {doc,<<\"_design/fastview\">>,\n {1,\n [<<8,240,229,73,29,55,237,140,209,212,55,78,252,52,73,20>>]},\n {[{<<\"views\">>,\n {[{<<\"doge\">>,\n {[{<<\"map\">>,\n <<\"function(doc) { if (true) { emit(doc.id, 1); }};\">>}]}}]}},\n {<<\"options\">>,{[{<<\"seq_indexed\">>,true}]}}]},\n [],false,[]},\n <<\"doge\">>}],\n [{file,\"src/couch_changes.erl\"},{line,243}]},\n {fabric_rpc,changes_enumerator,2,\n [{file,\"src/fabric_rpc.erl\"},{line,328}]},\n {couch_btree,stream_kv_node2,8,[{file,\"src/couch_btree.erl\"},{line,783}]},\n {couch_btree,fold,4,[{file,\"src/couch_btree.erl\"},{line,220}]},\n {couch_db,changes_since,5,[{file,\"src/couch_db.erl\"},{line,1225}]},\n {fabric_rpc,changes,4,[{file,\"src/fabric_rpc.erl\"},{line,68}]},\n {rexi_server,init_p,3,[{file,\"src/rexi_server.erl\"},{line,139}]}]}"}
> {code}
> So it looks like we need to do a bit of work in fabric to make it aware of the fast_view optimisation.
> [1] https://gist.github.com/mikewallace1979/1f53f186e48bb888c256#file-output_admin_port-md
> [2] https://gist.github.com/mikewallace1979/1f53f186e48bb888c256#file-output_cluster_port-md
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)