The router->last_written is used to store the position where the last event was
written. The replication header is also stored in a separate structure in
the router which is used later when the last packet of a multi-packet event
arrives.
Now, qc_mysqlembedded is linked against MySQL's embedded library,
and MaxScale itself against Connector-C.
So, in order to build MaxScale, Connector-C must be installed.
This has been tested with Connector-C 2.2.1.
The build variable MYSQLCLIENT_LIBRARIES is no longer used.
Earlier the same (or almost the same) code was duplicated in
several places.
A conflicting declaration was also removed. There was no
implementation for that declaration.
http://bugs.skysql.com/show_bug.cgi?id=665http://bugs.skysql.com/show_bug.cgi?id=664http://bugs.skysql.com/show_bug.cgi?id=649
dcb.c:dcb_final_free: (665):set dcb->session->client pointer to NULL so that it won't be read anymore and other threads won't try to close it.
dcb_final_free:(664):don't free dcb->data, it is either freed in session_alloc if session creation fails or in session_free only.
session.c:if session creation fails, free dcb->data and remove links between client DCB and session.
mysql_backend.c:(665):gw_backend_close:check that session->client isn't NULL and that client DCB's state is still polling before calling dcb_close for it.
mysql_client.c:gw_mysql_do_authentication:if anything fails, and session_alloc won't be called, free dcb->data.
mysql_common.c:gw_send_authentication_to_backend:if session is already closing then return with error.
readwritesplit.h:Removed invalid macros which assumed that ROUTER_CLIENT_SES->rses_backend_ref always pointed to valid and used backend reference and thus included potential risk of NULL-pointer refernce.
mysql_backend.c and mysql_client.c:avoid executing CHK_PROTOCOL(p) after original DCB has been released the memory.
readwritesplit.c:Replaced RSES_CLEINT_DCB macro with a function which returns client DCB for a given router client session.
mysql_mon.c: Added back server state logging to Debug build.
query_classifier.cc: removed some extra debug code, cleaned up a bit function documentation.
mysql_client_server_protocol.h, mysql_backend.c, mysql_common.c: changed some variables to signed ones to enable checking of calculations in the code.
skygw_utils.cc: removed erroneous debug assertion.
if (func.auth ==)gw_change_user->gw_send_change_user_to_backend is called before backend has its scramble, auth packet is set to backend's delauqueue instead of writing it to backend. When backend_write_delayqueue is called COM_CHANGE_USER packets are rewritten with backend's current data.
log_manager.cc: fixed block buffer overflow. Queries are logged to trace log and long queries exceed the bufsize in length. Those were written beyond allocated memory areas.
mysql_client_server_protocol.h: added mysql_protocol_state_t to indicate whether MySQL protocol object is allocated, usable or freed. Freed means that memory allocations made by the protocol are freed. That is, command history etc.
mysql_backend.c: gw_backend_hangup and gw_error_backend_event used to call error handling function although session was already closing. Added check for session state.
mysql_client.c: route_by_statement lost some packets in case where query was sent in multiple packets.
mysql_common.c: gw_MySQL_get_next_packet failed in packet handling with route_by_statement. When multi-packet query was merged into one, packet type wasn't copied.
protocol_archive_srv_command and mysql_protocol_done didn't have proper locking in place which lead to occasional crashes.
session.c:session_setup_filters : fixed memory leak
hintparser.c: added token_free for HINT_TOKENs and fixed a few memory leaks.
mysql_client_server_protocol.h: added mysql_protocol_done which frees memory blocks pointed to by protocol members. Those can't be freed in dcb.c because dcb.c doesn't know about protocol's members.
mysql_backend.c:gw_backend_close: fixed memory leak
mysql_client.c: gw_client_close: fixed memory leak
mysql_common.c: added implementation of mysql_protocol_done
:protocol_archive_srv_command: tried to fix memory leak. Some memory is still leaking according to valgrind. Removed use of uninitialized local variable len.
readwritesplit.c:execute_sescmd_in_backend: fixed a memory leak - visible only in DEBUG=Y build.
Fixed bug in session command resul handling. In case where backend sent error message the session command cursor wasn't updated properly.
Added check to bref_clear_state, if bref's waiter counter would go negative, decrement to global operation counter is skipped.
Added server command list structure which is included in MySQLProtocol. It holds command and number of response packets the command causes backend server to send as a response. Added set of functions related to protocol command and response packets counting etc.
Rwsplit handles ERRACT_NEW_CONNECTION by clearing backend reference, removing callbacks and associating backend reference with new backend server. If it succeeds and the router session can continue, handleError returns true. Otherwise false. When ever false is returned it means that session must be closed.
Rwsplit now tolerates backend failures in a way that it searches new backends when monitor, backend, or client operation fails due to backend failure.
Added a lot of logging to error, trace and message logs which should help the user to handle errors which can't be automatically resolved, like attempt to use nonexisting database.
For each session command a sescmd property is created and added to the end of list of session commands. List is owned by router client session and it includes all session commands from the beginning of router session.
Router maintains an individual session command cursor for each backend. A cursor refers to the first session command which the corresponding backend server haven't yet responded yet.
When response message arrives at any time from backend, first it is checked whether backend's cursor is active. Cursor is active if a session command is routed to backend and the backend haven't responded to it yet. If cursor is active, next it is checked whether the current session command property has been responded by other backend. If both are true, then response message is sent to client as is. If session command response is routed to client already, the arrived response is discarded.
