The handler callback should now return a bitmask with bits set
according to what it did when it was called. That way the actual
statistics gathering can be done in poll_waitevents() and the
handler need not be aware of any thread structs.
Actually, the only thing that needs any assistance is accept handling,
because in poll_waitevents() we do not know whether a READ event
relates to a listening or a normal socket, that is, should the
event be counted as an accept or as a read.
This is just a first step in a trial that will allow the addition
of any file descriptor to the general poll mechanism and hence
allow any i/o to be handled by the worker threads.
There is a structure
typedef struct mxs_poll_data
{
void (*handler)(struct mxs_poll_data *data, int wid, uint32_t events);
struct
{
int id;
} thread;
} MXS_POLL_DATA;
that any other structure (e.g. a DCB) encapsulating a file descriptor must
have as its first member (a C++ struct could basically derive from it).
That structure contains two members; 'handler' and 'thread.id'. Handler is a
pointer to a function taking a pointer to a struct mxs_poll_data, a worker thread
if and an epoll event mask as argument.
So, DCB is modified to have MXS_POLL_DATA as its first member and 'handler'
is initialized with a function that *knows* the passed MXS_POLL_DATA can
be downcast to a DCB.
process_pollq no longer exists, but is now called process_pollq_dcb. The
general stuff related to statistics etc. will be moved to poll_waitevents
itself after which the whole function is moved to dcb.c. At that point,
the handler pointer will be set in dcb_alloc().
Effectively poll.[h|c] will provide a generic mechanism for listening on
whatever descriptors and the dcb stuff will be part of dcb.[h|c].
A module can now declare a path parameter for a directory that does not
yet exist. If the directory does not exist, MaxScale will create the
directory with the requested permissions.
This number (defaults to 1) sets how many times mon_connect_to_db
will try to connect to a backend before returning an error. Every
connection attempt may take backend_connect_timeout seconds to
complete.
Also refactored code a bit. Renamed mon_connect_to_db to
mon_ping_or_connect_to_db, since it does not connect if the connection
is already alive.
New parameter added to maxsrows filter:
max_resultset_return=empty|error|ok
Default, 'empty' is to return an empty set, as the current
implementation.
'err' will return an ERR reply with the input SQL statement
'ok' will return an OK packet
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 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 contents of the existing filter.cc was copied into filter.c that
subsequently was renamed to filter.cc.
The way the session is called as the last filter in the filter chain
is really dubious and ought to be rearranged so that the blind casting
of a session to a filter and back is not needed.
By default, only the essentials - the type and the operation - of
a statement will be collected and only if fields, tables, functions
and databases are explicitly asked for, will they be collected.
However, a statement will be parsed at most twice; if parsing is
needed a second time then all information will be collected.
If it is known that some particular information is needed, then
qc_parse() can be called explicitly to ensure it is collected
at first parsing.
It is now possible to specify what information the caller is interested
in. With this the cost for collecting information during the query parsing
that nobody is interested in can be avoided.
- Non-GCC intrinsics alternative implementation removed. Let's worry
about the absence of the intrinsics once/if that becomes relevant.
- Spinlock release now performed using __sync_lock_release, as per
svoj's advice.
- while-looping on the variable used as lock removed, so it no longer
need to be volatile.
- Boolean function returns bool.
- Size of profiling counters increased.
- Risk for division-by-zero removed.
- Documentation moved from implementation to header.
If a server points to a local MaxScale listener, the permission checks for
that server are skipped. This allows permission checks to be used with a
mix of external servers and internal services.
The static module capabilities are now used to query the capabilities of
filters and routers. The new RCAP_TYPE_NOAUTH capability is also taken
into use. These changes removes the need for the `is_internal_service`
function.
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.
This is a list of servers, separated by commas. When queried as a
config setting, returns a null-terminated array of SERVER*:s. The
commit includes a serverlist parsing function, which should probably
be used anywhere a similarly formed string is parsed.
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 process and thread initialization/finalization of the query
classifier plugins is handled using the process and thread
initialization/finalization functions in the module object.
However, the top-level query classifier will also need to perform
process and thread initialization when transaction boundaries are
detected using regular expressions.
The connector plugin directory can now be controlled with the
`connector_plugindir` argument and configuration option. This should allow
the connector to use the system plugins if the versions are binary
compatible.
Replaced calls to mysql_options to mysql_optionsv as the former is
deprecated in Connector-C 3.0 and the latter is supported in Connector-C
2.3.
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.
Thread-safe version of strerror; thread local buffer used for storing
the message. The performance penalty of a thread local buffer is not
likely to be significant, since this is only called in an error
situation that anyway is likely to interrupt the normal processing.
The authenticators should have a similar way to print diagnostic
information as filter and routers do. This allows the authenticators to
print the users in their own format.
In the future, all the diagnostic entry points should be changed so that
they return a structure that contains the information in a standard
form. This information can then be formatted in different ways by other
modules.
The get_users function now combines the functionality of the old get_users
and get_all_users. This removes large parts of similar code.
Removed the listener resources as MySQLAuth was the only one that used it.
The user data is now stored inside a SQLite3 database. By storing the data
inside a database, we remove the restriction that the previous hashtable
based implementation had.
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.
