jiangphcn commented on issue #1186: [WIP] Clustered purge mixed cluster upgrade URL: https://github.com/apache/couchdb/pull/1186#issuecomment-370373499 Still trying to think about downgrade and upgrade from pre-CP to Clustered Purge. There is another situation where database are created after we upgrade to Clustered Purge. The database header will be created with purge tree instead of purge value, like ``` ([email protected])3> couch_db:open(<<"shards/c0000000-dfffffff/testy011-user1/db2.1520242912">>, []). {ok,{db,1, <<"shards/c0000000-dfffffff/testy011-user1/db2.1520242912">>, "/srv/db/shards/c0000000-dfffffff/testy011-user1/db2.1520242912.couch", {couch_bt_engine,{st,"/srv/db/shards/c0000000-dfffffff/testy011-user1/db2.1520242912.couch", <0.7078.55>,#Ref<0.0.69.200720>, [before_header,after_header,on_file_open], {db_header,7,0,0,nil,nil,nil,0,nil,184,1000, <<"6139f441"...>>, [{...}], 0,...}, false, {btree,<0.7078.55>,nil, #Fun<couch_bt_engine.id_tree_split.1>, #Fun<couch_bt_engine.id_tree_join.2>,undefined, #Fun<couch_bt_engine.id_tree_reduce.2>, {deflate,6}}, {btree,<0.7078.55>,nil, #Fun<couch_bt_engine.seq_tree_split.1>, #Fun<couch_bt_engine.seq_tree_join.2>,undefined, #Fun<couch_bt_engine.seq_tree_reduce.2>, {deflate,6}}, {btree,<0.7078.55>,nil, #Fun<couch_bt_engine.local_tree_split.1>, #Fun<couch_bt_engine.local_tree_join.2>,undefined,nil, {deflate,6}}, {deflate,6}, {btree,<0.7078.55>,nil,undefined,undefined,undefined, #Fun<couch_bt_engine.purge_tree_reduce.2>,snappy}, {btree,<0.7078.55>,nil,undefined,undefined,undefined, #Fun<couch_bt_engine.purge_tree_reduce.2>,...}}}, <0.7077.55>,nil,0,<<"1520242912784404">>, {user_ctx,null,[],undefined}, [],undefined,nil,nil,nil, [{default_security_object,[]}, {n,"3"}, {q,"8"}, {placement,undefined}], undefined}} ``` If we need to downgrade for such database, we might have to start without any purge history. Or other thoughts? @davisp
---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: [email protected] With regards, Apache Git Services
