Server creation and allocation are now the same apart from the fact that
allocation only adds the server to the running configuration where as the
creation of a server also persist it to disk.
The server serialization should not be seen through the server.h API. This
allows the serialization method to change without actually having to
change the interfaces.
When a server is created via MaxAdmin, it will be serialized to disk. This
allows created servers to be retained through a restart of MaxScale.
Currently, all serialized objects are stored in one folder and there is no
structure in the created files. In the future, servers could be created
under a `servers` subdirectory so that it is easier to see what was
added. Whether there is a need for this will be seen.
The address, port, monuser and monpw parameters of an existing server can
be changed at runtime. The support for enabling SSL will come in a later
commit.
Allowing servers to be modified could also be done by destroying and
recreating them. Since the servers are never actually destroyed, it is
better to allow the alteration of the existing ones.
The `add server` command accepts a server name and either a service name
or a monitor name. It will add servers to services and monitors. Since all
monitors use the MONITOR_SERVER structures directly, the monitors need
to be stopped before new servers are added to them
The debugcmd parameter processing didn't actually allow the maximum number
of parameters to be passed to the function. The detailed help text was
never printed and most of them were only duplicates of the short
description.
Before a query is routed to a backend, the status of the server reference
is checked. This allows the servers that are removed from a service to be
ejected from the list of active servers for active sessions.
The createInstace, newSession, closeSession and freeSession functions were
cleaned up and reorganized to be a bit clearer for the reader. Removed
unnecessary comments and replaced them with ones that explain what's
happening in the code.
Removed unused linked lists from both sessions and instances and replaced
them with better alternatives. This should improve performance since new
session don't have to acquire the instance level lock to put themselves
into the session list.
Removed the use of the BACKEND structure and replaced it with the use of
the SERVER_REF structure of the service. This allows dynamic changes to be
made to the list of servers.
Cleaned up parts of the code and removed obsolete or useless
functions. The schemarouter module could do with some refactoring since it
derives from readwritesplit.
The BACKEND structure in readconnroute is now replaced with the use of the
SERVER_REF structure of the service. This allows dynamic changes to the
list of servers to be made.
The readwritesplit now understands that the amount of servers can change
and some of the items in the list of server references aren't in use. This
allows dynamic changes to the number of servers used by readwritesplit.
Servers can now be added and removed from services which allows routers to
use them with new sessions. The routers don't fully use the new
functionality in the server references which prevents new servers from
being taken into use.
If shutdown has been initiated (via maxadmin or by sending a
SIGINT or SIGTERM) and a SIGTERM is received, the process
is terminated.
If shutdown has been initiated (via maxadmin or by sending a
SIGINT or SIGTERM) and a SIGINT (Ctrl-C) is received, a warning
is printed that shutdown is in progess. Then, if an additional
SIGINT is received, the process is terminated.
So, in practice:
- If MaxScale is running as a daemon, the first SIGTERM initiates
shutdown and a second one unconditionally terminates the process.
- If MaxScale is running in the console, the first Ctrl-C initiates
shutdown, the second prints a warning and the third terminates
the process.
This is to ensure that MaxScale can be forced to exit, in
case some thread is hung for whatever reason, and is thus preventing
the controlled shutdown.
Some of the tests depended on a working installation where modules are all
located at the default paths. These tests now explicitly set the module
directory which fixes the immediate problem.
Disabled the starting of services in the service test as this will fail
with real modules. The dummy internal modules aren't build and should be
removed in a later commit. In general, it might be better to do service
level testing outside the internal test suite.
Common capabilities are now defined in routing.h. The common
capabilities can be defined using bits 0 - 15.
Router capabilities are defined using bits 16-31 and filter
capabilities (should there ever be such) using bits 32-47.
So, to find out the capabilities of a service you only need to
OR the capabilities of the router and all filters together.
For instance, if a single filter needs statement based routing,
then that is what is done.
The dbusers.c was a MySQL protocol specific file which was used directly
by some of the modules.
Added a new return value for the loadusers authenticator entry point which
allows fatal failures to occur when users are loaded. Currently this is
only taken into notice when the service is first started. If a listener
later returns a fatal error, it is only logged but the service stays in
operation.
Moved the MySQLAuth authenticator sources and the tests that relate to
this module into a subdirectory in the authenticator
directory. Eventually, all authenticators could have a subdirectory of
their own.
The MySQL authenticator now injects the service user into the list of
allowed users if loading of database users fails. This allows the removal
of common code in the binlogrouter and maxinfo modules.
- Since the capabilities are a bitmask, it is better if an unsigned
integral type is used.
- Since the function is part of an ABI, it is better if an explicit
size is used.
- 64-bits so that there also is room for independent filter
capabilities.
Added find_package module for CMake which locates the Jansson libraries
and headers. This will make dependency checking easier and prevents build
failures due to missing dependencies.
In a subsequent change, the includes of server/core/*.c will be
cleaned up, and if there is a common set of include files, needed
by most, then a server/core/maxscale/core.h that includes those
will be introduced.
MAX_BUFFER_SIZE, which is used for limiting the amount of the data
read from a socket renamed to MXS_MAX_NW_READ_BUFFER_SIZE and moved
from gw.h to limits.h.
Consider removing altogether. Difficult to justify since non-blocking
reads are used and the amount of available data is known.
The general purpose stuff in skygw_utils.h was moved to utils.h
and the corresponding implementation from skygw_utils.cc to utils.c.
Includes updated accordingly.
Skygw_utils.h is now only used by log_manager and by mlist, which
is only used by log_manager. Consequently, skygw_utils.h was moved
to server/maxscale.
Utils.h needs a separate overhaul.
- STRERROR_BUFLEN moved to cdefs.h and renamed to MXS_STRERROR_BUFLEN.
Better would be to provide a 'const char* mxs_strerror(int errno)'
that would have a thread specific buffer for the error message.
- MIN and MAX also moved to defs.h as MXS_MIN and MXS_MAX.
- Now only mlist.h of the headers depend upon skygw_utils.h.
