This commit introduces changes that fix the relay master detection that
was broken by the merge from 2.1 into 2.2 by commit
1ecd791887994209eb29e56e1271f8c407cd0cdf.
In 2.2, the master server ID is used to detect whether a slave is actually
replicating from a master. The value is still displayed even if the slave
is not actively replicating from a master. The commit in 2.1 causes this
value to be stored unconditionally if it is available. By checking the
value of Last_IO_Errno and comparing it to a list of known error codes, we
know whether the slave is replicating properly.
The slave detection in 2.2 correctly identifies a broken slave with a
stopped IO thread. Due to this, the test case must be modified to check
that the relay master is not a slave if the IO thread is stopped.
If local address has been specified, then all connections created
using mxs_mysql_real_connect() will use that same local address as
well.
A system test has not been created as our VMs do not have more than
one usable IP-address. Locally it has been verified to work as
expected.
When MaxScale thinks that the master has failed, it tries to verify it by
seeing if the slave server is receiving events. There was a missing IO
thread status check in the slave_receiving_events function which caused
the failover to wait until the verification timed out.
The relay master detection logic also lacked a check for the slave SQL
thread status. The code should check the state of the SQL thread to
determine whether the server is actually a functional slave to a master.
The fix causes a regression in the failover functionality as there is a
dependency between the slave's master ID and how the failover
performs. This dependency should not exist but fixing it causes a problem
with the mysqlmon_rejoin_bad2 test.
The variable containing the number of workers must be updated
only after the workers have been successfully created.
Failure to do this led to crash in Worker::shutdown_all() if a
terminating signal was received after the worker initialization
had failed.
Instead of trying to figure out whether the kernel supports O_DIRECT
in conjunction with pipes, let's just use it and if it fails, try
without O_DIRECT.
Case in point, based on circumstantial evidence it seems that in a
container context, it may appear as if the kernel supports O_DIRECT
when it in reality does not. So better to use brute-force.
With the `allow_master_change` parameter enabled, sessions can start using
a different master node if one is available. This will not prevent
sessions from closing if a write query is received while no master
replacement is available.
If a listener section specifies both a 'socket' and a 'port' the
creation will fail with a clear error message.
If 'address' and 'socket' is specified, there will be a warning that
the address is meaningless.
It is now impossible to create two listeners for a service that
would listen on the same port/socket (as before), but the error
message is now sensible and provides detailed information to the
user.
Startup now done in a static method. Constructor initializes some values.
Config parameters loaded in a separate method. Some things still need
looking.
When MaxScale is starting, the loading of the listeners can take a while
if there are a large number of services and users to load. To signal this
to the user, progress messages should be logged after every service is
started.
When backend SSL connections were created, the connection creation was
done twice. This was due to the lacking detection of an already
established SSL connection.
When readwritesplit receives a reply from a backend, an info level log
message is now logged. This allows easier debugging of situations where
replies aren't properly returned by the router.
When MaxScale is starting, the loading of the listeners can take a while
if there are a large number of services and users to load. To signal this
to the user, progress messages should be logged after every service is
started.
If a DCB is closed before a response to the handshake packet is received,
the DCB's session will point to the dummy session. In this case no error
should be written to the DCB.
This is a cherry-pick of commit f53e112bf49766f1cc55516c2d7ee571461d483f
from the 2.2 branch.
If the avrorouter is being build and the required libraries are not found,
the configuration process should fail. Adding the command to bypass this
into the error message should make it easier to disable this part if it is
not needed.
The message now states the impliciations of missing permissions. If the
MaxScale user does not have the permissions to view all databases, it will
only see its own databases.
A linefeed is whitespace, so given the rules
"\n"+ return '\n'
{SPACE} ;
a line consisting of space followed by a linefeed, will be matched
as space and not as a linefeed and hence will cause the parser to
barf.
After a temporary table is created, readwritesplit will check whether a
query drops or targets that temporary table. The check for query type was
missing from the table dropping part of the code. The temporary table read
part was checking that the query is a text form query.
Added a debug assertion to the query parsing function in qc_sqlite to
catch this type of interface misuse.
