The std::shared_ptr type was used instead of std::tr1::shared_ptr. A NULL
pointer was also implicitly cast into a Backend pointer which caused
compilation problems on some platforms with the tr1 version of shared_ptr.
The SERVER_REF and DCB members of the Backend class are now
private. Access to the stored SERVER_REF is provided with the backend()
function. No accompanying setter function is provided as the backend
server should not change during the lifetime of the session.
The creation of the internal DCB is hidden behind the connect()
function. It simplifies the process of connecting to a server by removing
the need to manually do the bookkeeping of the server reference connection
counts. Access to the DCB is provided by the dcb() function.
The closing of the backend is done with the close() function which
contains the code that was previously in closeSession. If the backend
isn't closed when the destructor is called, it will be done
automatically. This should prevent connection leakage.
The pending command queues and the methods used to write them are now also
internal to the backends. They are simple wrappers around dcb->func.write
and the interfaces provided by the Buffer class. The mapping command queue
is still public. It needs to be combined with the generic command queue.
The schemarouter now uses shared pointers. This removes the need to copy
the class.
Following changes move the member variables inside the Backend class.
The functions that handle Backend classes are now methods of the class
itself.
Prefix all member variables with `m_` to distinct them from other
variables.
Changed the backend_ref_t struct into a Backend class. Replaced static
arrays with lists. Altered functions to make the code compile.
Further refactoring is needed, a part of the functions should be moved
into this new class.
Configuration errors can be resolved before the instance is created. This
avoids the unnecessary throws that were generated when an error occured.
As the configuration is stored in the router, the router sessions can use
a pointer to it instead of copying it locally. This should avoid some
unnecessary copying if more complex configuration parameters are added.
The use of a pointer instead of a reference conveys the message that the
lifetime of the object being pointed can, and most likely will, exceed the
lifetime of the function.
Also shuffled the member variables and internal functions around and
removed unneeded function declarations.
Cleaned up the headers, removed unused structures. Changed some members to
strings instead of char arrays. Switch to router templates should now be
easier.
The sharding implementation now uses a class to abstract the details of
the shard. This allows for different design where each session makes a
copy of the global shard map which is then used for the duration of the
session. In addition to making the desing a bit clearer to understand, it
also removes lock competition between threads.
Due to the change to C++, the main entry points need to be wrapped in the
exception-safety macros. The next step in the refactoring will be to use
the router template. This will remove the need to manually define them.
The schemarouter now uses the new session commands. It uses a standard
library container to manage the execution and storage of session commands.
The session command history is disabled until a more complete refactoring
can be done.
Some of the protocol modules use ssize_t instead of size_t.
Split the function that counts the number of response packets a session
command will receive into two parts. This allows it to be reused
elsewhere.
The binlogrouter error handling closed the DCB twice. This was caused by
the change in the way the DCB error handling is done.
The protocol modules now also call the error handling routine even if the
router session is NULL. This enables the binlogrouter to manage
authentication failures correctly instead of trying to reconnect again.
Previously, MaxAdmin would interpret any non-option words in the
command line as either a filename or, if the file could not be opened,
as MaxAdmin commands. This made it possible to mix filenames and
commands if there was a matching filename in the folder. For example
"maxadmin show services" would read commands from a file named
"show services" if it existed. This update removes this feature. To
read commands from a file, use either shell redirection "maxadmin <
mycommands" or the "source"-command inside maxadmin.
General code cleanup. Routing error detection now more robust.
Remove some unused code. Debug messages now use "unique_name" when
referring to servers.
Supports hint types:
-master
-slave
-named server
-all
A default action, which is performed when no hint exists or on error,
can be set. The different actions are analogous to the hint types.
A maximum connection number for slaves can be set. If more slaves are
configured for the service, the filter will rotate slaves for new sessions.
Within a session with multiple slaves, the "route_to_slave"-hint will
also rotate among the slave backends.
The readwritesplit now sends COM_PING queries to backend servers that have
been idle for too long. The option is configured with the
`connection_keepalive` parameter.
