The storage_rocksdb version is now stored to the database. That will
ensure that should the format (key content, length, etc.) change, we
can will detect whether a database is too old and take action.
The databases targeted by a query are now included in the key.
That way, two identical queries targeting a different default
database will not clash.
Further, it will mean that queries targeting the same databases
are stored near each other, which is good for the performance.
The concept of 'allowed_references' was removed from the
documentation and the code. Now that COM_INIT_DB is tracked,
we will always know what the default database is and hence
we can create a cache key that distinguises between identical
queries targeting different default database (that is not
implemented yet in this change).
The rules for the cache is expressed using a JSON object.
There are two decisions to be made; when to store data to the
cache and when to use data from the cache. The latter is
obviously dependent on the former.
In this change, the 'store' handling is implemented; 'use'
handling will be in a subsequent change.
The mysqlmon simple failover mode allows it to direct write traffic to a
secondary node. This enables a very simple failover mode with MaxScale
when it is used in a two node master-slave setup.
With this change, the cache will be aware of which default database
is being used. That will remove the need for the cache parameter
'allowed_references' and thus make the cache easier to configure
and manage.
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.
The canonical form of the query should ignore changes in whitespace as the
semantics of the query stays the same regardless of the amount of
whitespace.
The TARBALL variable controls if a special tar.gz package is built when
packages are generated. This package has a different directory structure
compared to the RPM/DEB packages.
If RPM/DEB packages are built, tar.gz packages are not built. This makes
RPM/DEB generation faster and allows tarballs to be built separately with
a proper directory structures.
The MYSQL_* authentication return codes are now in gw_authenticator.h so
that all authenticators can use them. Also dropped the MYSQL_ prefix from
the return codes and added AUTH_INCOMPLETE for a generic
authentication-in-progress return code.
The authenticators can now declare the authentication plugin name. Right
now this is only relevant for MySQL authentication but for example the
HTTP module could implement both Basic and Digest authentication.
When a query has been sent to a backend, the response is now
processed to the extent that the cache is capable of figuring
out how many rows are being returned, so that the cache setting
`max_resultset_rows` can be processed.
The code is now also written in such a manner that it should be
insensitive to how a package has been split up into a chain of
GWBUFs.
The `create_grants` scripts allow users to be easily "copied" to
MaxScale. It queries the backend for grants for all users and converts
them into similar grants for the MaxScale host.
The `create_roles.sql` is a small set of queries which creates two utility
roles, `proxy_authenticator` and `proxy_monitor`. These roles can be
assigned to the actual service and monitor users with a single grant
command.
MaxScale shouldn't require the service and monitor user checks. It makes
sense to disable the checks to speed up the startup process when the user
knows that the permissions are OK.
Session command responses with multiple packets could be spread across
multiple, non-contiguous buffers. If a buffer contained a complete packet
and some extra data but it wasn't contiguous, the debug assertion in
gwbuf_clone_portion would fail. With release builds, it would cause
eventual out-of-bounds memory access when the response would be sent to
the client.
When a backend causes an error and it should be sent to the client, the
backend reference was closed but the waiting results state was not
cleared. This caused a debug assertion to be hit.
