Added function pointer array which is indexed by enumerated selection criterias.
Selection criteria can now be switched by modifying config file and reloading it.
The option is reloadable in the same way as max_slave_connections parameter. Option value determines which sort function is called before to sort backend server pointers before selecting them and establishing connections to backends.
Added missing makefile to server/modules/routing/test . It is needed for system testing. Prior this fix, 'make testall' failed because the makefile was missing.
In practice, 'reload config' reads config file and updates config parameters of rwsplit router service. In addition to that there is a version number indicating what generation of configuration service holds. When router instance is created (when MaxScale is started) service's config version is copied to router intance. Whenever new client connection (rwsplit session) is started, router instance's config version is checked against that of service's. If versions differ, service's config data is copied to router instance. New session will be started with router instance's config values.
query_classifier.cc use of uninitialized value in skygw_stmt_causes_implicit_commit
config.c crashed if module load failed, use of unitialized value
load_utils.c pretty-printed error
service.c use of uninitialized value in service_add_qualified_param
modules.h function prototype
readwritesplit.c memory leaks
1. in query_classifier.cc autocommit_enabled, and transaction_active variables maintained their values across different sessions. Now those values are stored in each router_client_ses object.
2. As a part of implementation of MAX-95 session variables were added to BACKEND struct which is shared with all sessions using the SERVICE which the particular BACKEND serves. Now each router_client_ses object has a backend reference struct which includes pointer to BACKEND, DCB and to session command cursor.
Added test - set_autocommit_disabled.sql, test_after_autocommit_disabled.sql - to check that session variable is discarded when session where it belongs terminates.
Parameter it read from config file to CONFIG_CONTEXT's parameter list. It is qualified in service.c:service_set_slave_conn_limit and if qualified, the qualified integer value and the value type are copied to the CONFIG_PARAMETER structure.
This CONFIG_PARAMETER struct is cloned (=copied to different memory area) and linked to RW Split SERVICE struct.
When RW Split router_instance is created in readwritesplit.c:createInstance, the value is copied to (new) rwsplit_config_t structure from SERVICE's parameter list.
When new routing session is created in readwritesplit.c:newSession, the rwsplit_config_t structure is copied to ROUTER_CLIENT_SES struct and the actual max_nslaves value is calculated from the config value (if percentage is used).
Tests and many error handling branches are missing but functionality seems to be working.
Increased skygw_query_type_t to 16 bits, and corrected the way how those bit fields are checked.
Added tests for cases where autocommit is disabled and corrected old tests.
. That means that (at least) the first packet in the message is response to session command. Then if the response is alread
y forwarded to client it is discarded. Otherwise it is routed to client and the command is marked as responded so that the o
ther backend knows to discard its duplicate response.
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.
This implementation doesn't guarantee execution order between session commands and queries
if other backend server lags behind in session command execution.
In poll.c : moved processing of EPOLLERR and EPOLLHUP after processing of EPOLLIN and EPOLLOUT.
This ensures that COM_QUIT messages are read and routed forward before signals arrive (from local client/backend).
nection router stream is used and with read/write split router individual statements are passed to router.
Added new function to ROUTER_OBJECT : uint8_t (*getCapabilities)(ROUTER *instance, void* router_session); which is implemented in every route
r.
Added support for multi-statement packets in rwsplit router. In other words, if network packet includes multiple mysql statements, they are separated and passed to router one by one.
Multi-packet statements (those which exceeds network packet boundaries) are _not_ supported yet.
Added support for multi-statement packets.
This is an intermediate commit to save work. Code is not cleaned and there are debug prints and prototypes to be removed.
Session commands are identified by query clasisfier, and added to the session command property list in router client session object.
Session commands are then executed in existing backend servers but only one of them will reply to client.
dcb.c:dcb_write accept also dcb state DCB_STATE_NOPOLLING since it only means that dcb has been removed from epoll set but it is still possible to write to it.
Bug #384http://bugs.skysql.com/show_bug.cgi?id=384
session.h:added new state for SESSION, SESSION_STATE_ROUTER_READY which follows SESSION_STATE_READY. The difference is that ROUTER_READY is set only after router session is successfully created while READY means that session still lacks router.
session.c:set SESSION_STATE_ROUTER_READY when router is created.
mysql_backend.c:gw_read_backend_event, added SESSION_STATE_ROUTER_READY check before router session is closed. Changed chec kso that it doesn't block in infinite loop (although it shouldn't be possible anyway).
mysql_backend.c:gw_error_backend_event, added similar check before session is closed.
Added new argument '-s' which takes additional argument composed of list of logfile identifiers. Logfiles listed with '-s' will be written on main memory instead of disk. In practice, the log file in question will be written in /dev/shm but corresponding symlink is added to log directory. In the case of name conflicts with log files and links, a differentiating sequence number is included in hte name of the file. This, however, is done only when existing file is not writable or is of different type (symlink <> file).
Added new logfile LOGFILE_DEBUG whose contents will be largerly what was included up to date in trace log.
Disabled feature which spreads writes to log files to others because of bug (#338) in the way block buffers are managed.
Changed log manager parameters to match with the current implementation. List of arguments:
"-h - help\n"
"-a <debug prefix> ............(\"skygw_debug\")\n"
"-b <debug suffix> ............(\".log\")\n"
"-c <trace prefix> ............(\"skygw_trace\")\n"
"-d <trace suffix> ............(\".log\")\n"
"-e <message prefix> ............(\"skygw_msg\")\n"
"-f <message suffix> ............(\".log\")\n"
"-g <error prefix> ............(\"skygw_err\")\n"
"-i <error suffix> ............(\".log\")\n"
"-j <log path> ............(\"/tmp\")\n"
"-s <shmem log file ids> ........(no default)\n";
dcb.c
dcb_add_to_zombieslist, add dcb to the front of zombies list instead of inserting to the end of it.
gateway.c
Renamed shutdown_gateway to shutdown_server (Bug #131)
Call skygw_logmanager_init so that trace and debug logs are written to shared memory.
poll.c
dcb.h
Removed some dead code and references to unneeded mutexes.
debugcmd.c
Added enable/disable log command for debug log.
skygw_utils.cc
skygw_file_init now takes optional symlink name as a second argument. Symlink is created to point to the file being created.
resolve_query_type, added GSYSVAR_FUNC type for functions that read system variables and can be executed in Maxscale instead of backend server.
dcb.c
dcb_read, if read returns value <= 0 and if error is EAGAIN/EWOULDBLOCK so there was nothing to read in sthe socket, that is not an error because some other thread may have read the data that was expected to be available.
mysql_backend.c
gw_read_backend_event, used dcb->authlock to ensure that dcb's protocol state is read and modified serially. This removes issues with false authentication failures which may happen when two threads modify and read the state without any control.
mysql_client.c
removed dead code.
readconnroute.c, readwritesplit.c
removed invalid assert which assumed that spinlock can not have larger value than one when itis locked.
poll.c
Removed mutex from epoll_wait.
Removed read and write mutexes from poll_waitevents.
session.c
If session_alloc fails, instead of calling directly free(session), call session_free, which decreases refcounter and only frees session when there are no references left.
Added session_unlink_dcb function which removes link from session and optionally sets the dcb->session pointer to NULL.
readconnection.h, readwritesplit.h
Added check fields to ROUTER_CLIENT_SES strct as well as lock, version number (not used yet) and closed flag.
mysql_backend.c
gw_read_backend_event: if backend_protocol->state was set to MYSQL_AUTH_RECV, function returned, which was unnecessary. If mysql state became MYSQL_AUTH_FAILED, router client session was closed. Removed unnecessary NULL checks because rsession is not allowed to be NULL. Similarly, removed other NULL checks and replaced them with asserts checking that router client session is not NULL at any phase.
mysql_client.c
Removed unused code blocks. Polished log commands. Replaced router client sessions NULL checks with asserts.
mysql_common.c
mysql_send_custom_error: if called with dcb == NULL, return.
readconnroute.c
Replaced malloc with calloc. Added functions rses_begin_router_action and rses_exit_router_action. If router client session is not closed, they take a lock and release it, respectively. Those functions are used for protecting all operations which modify the contents of router client session struct.
readwritesplit.c
Identical changes than in readconnroute.c
skygw_debug.h
Added check number and - macro for ROUTER_CLIENT_SES, and added COM_QUIT to STRPACKETTYPE.
resolve_query_type, traverse through the list of items of thd->free_list, identify functions and reason query type according to the function type. This phase can only increase the restrictiviness level of the query.
query_classifier.h
Added new query type QUERY_TYPE_LOCAL_READ, for functions that can be executed in Maxscale. This type is the least restrict
ive query type. It is not used currently.
testmain.c
Added a few test cases and fixed expected return values for query type tests.
readwritesplit.c
polish
skygw_debug.h
Added string macro for Item types.
The routine if called from backend will ido:
1 reply error messages to client closing or not the session
2 open a new backend connection
An action flag is passed to the routine.
dcb_write earlier returned an error (== 0) if errno was not set and other conditions were satisfied. In practice, if write was done in write queue, queue pointer was not updated and dcb_write returned and error. Changed the error detection condition so that it requires errno being set, at least.
readwritesplit.c
Clean up.
tuned error printing and log writing output format
dcb.c :
dcb_connect, check return value of poll_add_dcb and behave accordingly.
dcb_write, in case of SIFPIPE, only write to trace log.
dcb_close, dassert with incorrect dcb states.
gateway.c :
added file_write_header to print header similar than in logs to stderr.
main, add signal handler for SIGPIPE
poll.c :
poll_remove_dcb, don't fail if dcb is in NOPOLLING or in ZOMBIE states.
poll_waitevents, write EPOLLHUPs to trace log, don't even attempt to write to closed socket.
readconnection.h :
shortened comment.
readwritesplit.h :
replaced generic names with more specific ones.
httpd.c :
Check listen return value and behave accordingly.
mysql_backend.c :
Tiny clean up.
mysql_client.c :
gw_MySQLListener, Check listen return value and behave accordingly.
mysql_common.c :
Shortened a header.
telnetd.c :
telnetd_listen, check listen return value and behave accordingly.
readconnroute.c :
Tuned log writing format.
readwritesplit.c :
Added function search_backend_servers, which chooses suitable backend and master server among those known by Maxscale. Fixed clean-up routines. Not ready yet but works somehow.
testroute.c :
Cleanup.
skygw_utils.cc :
Log writing clean up.
session.c: Replaced free(session->router_sesision) with call to freeSession callback
users.c: Removed reference to uninitialized variable.
router.h: Added freeSession callback to function block.
mysql_backend.c: try to ensure that client dcb is still listening in epoll_wait when writing reply to it.
mysql_common.c: assert debug build is mysql_protocol_init is called with dcb == NULL
readconnroute.c, readwritesplit.c, debugcli.c and testroute.c : Added freeSession to function block and an inmplementation of it.
