The functions used to track the resultset EOF packets now expose the
position of the end of the result set. This allows the modules that use
them to check if more results exist in the same buffer.
Added the status bits for OK and EOF packets to the mysql.h protocol
header. This can be used to check for various state changes that happen in
the session. Currently the status bits are only used to detect if more
results are expected.
When statement based routing was used, it was possible that the current
statement being executed wasn't properly updated. Readwritesplit requires
it to track whether a command will create a response.
When batched queries are done through readwritesplit, it will now handle
them one by one. This allows batched queries to be used with
readwritesplit but it does impose a performance penalty when compared to
direct execution on the backend.
This reverts commit f3c83770903151a0a3b53593c3e05fa0af94cd5f. The
functionality was used implicitly by modules that declare the
RCAP_TYPE_CONTIGUOUS_OUTPUT capability.
The RCAP_TYPE_STMT_OUTPUT is not used in its previous form. It can be
altered to route only complete packets back to the client. This allows
routers to do safer parsing on the results.
When log messages are written with both address and port information, IPv6
addresses can cause confusion if the normal address:port formatting is
used. The RFC 3986 suggests that all IPv6 addresses are expressed as a
bracket enclosed address optionally followed by the port that is separate
from the address by a colon.
In practice, the "all interfaces" address and port number 3306 can be
written in IPv4 numbers-and-dots notation as 0.0.0.0:3306 and in IPv6
notation as [::]:3306. Using the latter format in log messages keeps the
output consistent with all types of addresses.
The details of the standard can be found at the following addresses:
https://www.ietf.org/rfc/rfc3986.txthttps://www.rfc-editor.org/std/std66.txt
The new type allows routers to send queries and get complete result sets
as a response. This allows the routers to easily send commands that create
result sets and which are parsed by the router.
Currently only the schemarouter benefits from this new capability as it
generates the database mappings by parsing the output of a SHOW DATABASES
query.
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.
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.
The static capabilities declared in getCapabilities allows certain
capabilities to be queried before instances are created. The intended use
of this capability is to remove the need for the `is_internal_service`
function.
Transaction boundaries can now be detected using regexes.
All else being equal, it gives a 10% performance improvement
compared to qc-based detection.
In a subsequent change, mysql_client.c will be modified to use
qc_get_trx_type_mask() instead of qc_get_type_mask().
Currently the use of regex matching is turned on using an
environment variable. That will change.
The core now provides a simple function to close a session. This removes
the need for the modules to directly call the API entry points when the
session should be closed. It is also in line with the style that other
objects, namely the DCBs, use. This makes the new session_close very
similar to dcb_close.
The client protocol module can resolve whether a password was used based
on the information the authenticators gather before authentication is
done. It uses the authentication token length as the basis on which it
makes the decision.
The client connection and the server listener sockets used largely similar
code. Combining them allows for simpler protocol code.
Cleaned up parts of the DCB listener creation and moved the parsing of the
network binding configuration to a higher level.
The socket creation code in mysql_backend.c wasn't MySQL specific and it
could be used for all non-blocking network connections. Thus, it makes
sense to move it to a common file where other protocol modules can use
it.
The address resolution code now uses `getaddrinfo` to resolve all
addresses instead of manually handling wildcard hosts. This allows the
same code to be used for all addresses.
Both the listeners and servers now support IPv6 addresses.
The namedserverfilter does not yet use the new structures and needs to be
fixed in a following commit.
Currently the only situation where a user needs to be authenticated after
the initial authentication is when a COM_CHANGE_USER is being
executed. This was previously handled by directly calling a function in
the MySQLAuth authenticator.
The new entry in the API of the authenticators is very specific to MySQL
and should be reviewed once other protocols are added.
Refactored common code into a reusable function. Now all of the backend
error handling uses the same function.
Moved responsibility of the DCB error handling tracking to the backend
protocol. The routers no longer need to manage the
`dcb->dcb_errhandle_called` variable of the failed DCB.
Removed calls to handleError with client DCBs as parameters. All of the
routers close the DCB given to handleError if it is a client DCB. The only
time the error handler would be called is when the routeQuery function
fails. The handleError call is redundant as the router already knows that
the session should be closed when it returns from routeQuery.
Removed unused spinlocks from DCBs, sessions and the MySQL protocol
structs. They were used in a context where only one thread has access to
the structure.
Removed unused member variables from DCBs.
Currently the only situation where a user needs to be authenticated after
the initial authentication is when a COM_CHANGE_USER is being
executed. This was previously handled by directly calling a function in
the MySQLAuth authenticator.
The new entry in the API of the authenticators is very specific to MySQL
and should be reviewed once other protocols are added.
The transaction tracking now flags the transaction as open even when a
COMMIT/ROLLBACK is received. The next statement after the transaction is
closed resets the transaction state to inactive. This means that the end
of the transaction belongs in the transaction.
This allows all statements that belong to a transaction to be detected
with the transaction tracking functions provided by the core. With this,
the routing modules should have an easier time handling transactions.
When the transaction ends, it's good to know what type of a transaction
just ended. Currently, this will be used by readwritesplit to detect when
a read-only transaction ends.
All modules now declare a name for the module. This is name is added as a
prefix to all messages logged by a module. The prefix should help
determine which part of the system logs a message.
