{"comment":{"created_at":"2011-10-11T08:03:00Z","body":"[springmeyer] okay, thanks for the additional details.\r\n\r\nI have seen this error on linux/mac when \"multiprocess\" rendering is done wrong:\r\n\r\n\"server sent data (\"D\" message) without prior row description (\"T\" message) socket not open\"\r\n\r\nBasically something causes the connection to the database to be lost or corrupted. I don't have a solution at this point as I do not have a windows machine I can easily test on. But I would assume that this is a bug in the threading module on windows, that if we understood better we could potentially provide a catch or workaround within mapnik for...","updated_at":"2011-10-11T08:03:00Z","url":"https://api.github.com/repos/mapnik-org/mapnik/issues/comments/2358194","id":2358194,"user":{"avatar_url":"https://secure.gravatar.com/avatar/941f68386168a8a6b60f2529a7830af7?d=https://a248.e.akamai.net/assets.github.com%2Fimages%2Fgravatars%2Fgravatar-140.png","url":"https://api.github.com/users/artemp","id":59056,"login":"artemp"}},"action":"created","issue":{"number":579,"created_at":"2011-10-11T08:02:56Z","pull_request":{"diff_url":null,"patch_url":null,"html_url":null},"body":"We have encountered problems with using multithreading feature of \r\ngenerate_tiles.py: when using more than one thread, we get Mapnik exception \r\n\"RuntimeError: PSQL error\" from the src/plugins/input/postgis/connection.hpp \r\nat line 97 (Mapnik 0.7.1, WinXP SP3):\r\n\r\n\r\n{{{\r\n\r\n84:         if(!result || PQresultStatus(result) != PGRES_TUPLES_OK)\r\n85:         {\r\n86:             std::string s(\"PSQL error\");\r\n87:             if (conn_ )\r\n88:             {\r\n89:                 std::string msg = PQerrorMessage( conn_ );\r\n90:                 if ( ! msg.empty() )\r\n91:                 {\r\n92:                     s += \":\\n\" + msg.substr( 0, msg.size() - 1 );\r\n93:                 }\r\n94:                 \r\n95:                 s += \"\\nFull sql was: '\" + sql + \"'\\n\";\r\n96:             } \r\n97:             throw mapnik::datasource_exception( s );\r\n98:         }\r\n\r\n}}}\r\n\r\nThe SQL syntax of the executing query is OK and is working fine with one thread.\r\nMaybe the code here is somehow not MAPNIK_THREADSAFE aware?","comments":7,"title":"Multithreading error when using generate_tiles.py and PostGIS","updated_at":"2011-10-11T08:03:02Z","url":"https://api.github.com/repos/mapnik-org/mapnik/issues/579","id":1872219,"assignee":null,"milestone":null,"closed_at":null,"user":{"avatar_url":"https://secure.gravatar.com/avatar/941f68386168a8a6b60f2529a7830af7?d=https://a248.e.akamai.net/assets.github.com%2Fimages%2Fgravatars%2Fgravatar-140.png","url":"https://api.github.com/users/artemp","id":59056,"login":"artemp"},"html_url":"https://github.com/mapnik-org/mapnik/issues/579","labels":[{"name":"PostGIS_Input_Driver","url":"https://api.github.com/repos/mapnik-org/mapnik/labels/PostGIS_Input_Driver","color":"FFFFFF"}],"state":"open"},"legacy":{"issue_id":1872219,"comment_id":2358194}}