The master reference used by the readwritesplit sessions needs to be
reassigned if slave reconnection occurs. This happens because the
reference refers to a certain place in the backend reference array
instead of the actual backend reference and those places are mixed
when the array is sorted.
The monitors and services didn't use TLS when they connected to the
backend servers. Since there has been no proof of instability, TLS should
be enabled.
The error logging is now more detailed and tells why the connection is
being closed. This should help the user figure out what is happening when
write fails and the connection is closed.
Some of the master server status checks didn't check whether the server
was actually running. The macros in server.h should always be used instead
of manually inspecting the server status.
If a readwritesplit session is active, it should never connect to a new
master. This will lead to unexpected results as the session states aren't
consistent.
If an illegal DCB close is done with a backend DCB, it will log the server
where it was connected. This allows us to know whether the DCB was
connected to a master or a slave.
Added more debug assertions to readwritesplit code. The DCBs should never
enter the DCB_STATE_DISCONNECTED.
Removed useless debug log messages. The messages usually just flood the
logs with no use to the developers.
A debug assertion failed due to a NULL buffer but a non-zero packet
length. This was caused by a missing reset of the packet length after
freeing the buffers.
Some error messages were logged at INFO level and some had conditions that
prevent the logging. Removed these restrictions that an error situation is
always logged.
If a master_failure_mode was set to error_on_write, a reconnection to the
old master would happen after the following events:
- Master server fails and the connection is closed
- The master server recovers
- A slave fails and the connection is closed
- A replacement for the slave is searched
If these events took place, the master would be taken back into use with
an inconsistent session state.
Binlog server is already configured: if there is no pending transaction
a new binlog file is created after CHANGE MASTER.
If as START SLAVE is issued replication starts as usuale.
If maxscale is restarted the replication starts using the new created
file.
While configuring binlog server for the first time, master.ini not
existent, the specified MASTER_LOG_FILE is created in the $binlogdir.
If START SLAVE command is not issued the replication can start after
restarting maxscale as the binlog file exists.
When a COM_CHANGE_USER statement was executed, the new user credentials
were copied after the authentication message was sent. This caused the
COM_CHANGE_USER to always succeed the first time as it used the current
credentials. The user credentials would always lag behind by one.
When checksum is in use and there is an error in replication stream
master connection the blr_terminate_master_replication has no effect.
MXS-961: The checksum detection calls
blr_master_delayed_connect(router); and connection is scheduled again.
The fix will break the main loop as soon as the error indicator byte is
seen and no other computation will be done (such as checksum)
When a DESCRIBE <table> or a SHOW COLUMNS IN <table> query is done, the
actual query is performed on tables in the information_schema
database. This might be what actually happens on the backend server but
this information is not really useful when we need to know which database
the query targets.
By passing the actual table names instead of the underlying table names,
the schemarouter is able to detect where these statements should be
routed.
The default character set should be copied from the server so that
MaxScale appears to be the same. This fixes problems where utf8mb4
couldn't be taken into use because MaxScale would always send latin1 as
the server charset.
When the readwritesplit can't locate the master server when it's checking
the list of available servers, it logs an error if the original master
reference isn't in a valid state. This error should only be logged if the
server is in use but in an unexpected state.
When the authentication string was decoded from hexadecimal to binary, it
was possible that an out of bounds read was done if the length of the data
was not an even number.
The upgrade process removed the /var/lib/maxscale directory as the newer
version didn't use it. This can be fixed by installing an empty directory
into /var/lib/maxscale.
The return values of pcre2_match are now properly handled. A positive
match is a return value which is greater than or equal to zero. This fix
should give a small performance boost to as memory is no longer needlessly
allocated.
Previously a query like e.g.
delete t11.*, t12.* from t11,t12 where t11.a = t12.a;
would cause a leak. The code for freeing that memory was present
but commented out because it used to cause a crash.
Now no crash appears, so it would seem that the crash was caused
by something else that no longer is present.
The backend reference states should be cleared when a reconnection attempt
is made. Should the creation of a new DCB succeed, the backend should no
longer be closed.
