Description:
Bug 78777 (where idle threads showed a state as 'cleaning up') was fixed in 5.6.35, but the fix causes different behavior depending on whether you are using performance schema or not - the State data is different.
With performance schema:
show processlist;
Id User Host db Command Time State Info Rows examined Rows sent Tid
2 root localhost test Query 0 init show processlist 0 0 411285
Without performance schema:
show processlist;
Id User Host db Command Time State Info Rows examined Rows sent Tid
2 root localhost test Query 0 NULL show processlist 0 0 414212
How to repeat:
1. Build with performance schema (cmake -DWITHOUT_PERFSCHEMA_STORAGE_ENGINE=1; make -j32)
2. Start the server
3. Connect to the server
4. Issue a "SHOW PROCESSLIST;" command
5. Build without performance schema (cmake; make -j32)
6. Start the server
7. Connect to the server
8. Issue a "SHOW PROCESSLIST;" command
Suggested fix:
The problem is that the current location of setting the THD's state to INIT is occurring in code that is only executed via performance schema (net_after_header_psi()) and the code that calls this function doesn't appear to have access to the THD pointer.
I solved the problem by adding a call to "THD_STAGE_INFO(thd, stage_init);" in do_command() (sql/sql_parse.cc) after the packet has been fully read, but I don't know if this is the best location.
diff --git a/sql/sql_parse.cc b/sql/sql_parse.cc
index 6bfa5dd..7062c97 100644
--- a/sql/sql_parse.cc
+++ b/sql/sql_parse.cc
@@ -1098,6 +1098,7 @@ bool do_command(THD *thd)
goto out;
}
+ THD_STAGE_INFO(thd, stage_init);
packet= (char*) net->read_pos;
/*
'packet_length' contains length of data, as it was stored in packet
