The external config.h header defined functions and structures that are
intended to be used by modules. The internal header contains functions
that are used only by the MaxScale core.
To test the configuration validation and default value generation, the
functions needed to be refactored to allow parameters to be passed
directly to the function.
Some uses of monitorStart didn't pass the monitor parameters to the
function call. This caused runtime configuration of monitors to not have
any parameters as they never got their parameters.
Using the unique ID for the session is easier to use than an address. This
also allows the removal of all pointer values from the maxadmin output
which is never useful to the end user.
After upgrades, it is usually useful to see which version of MaxScale is
running. By adding a command, we can see the actual version of the running
daemon process instead of the version of the current binary.
The detailed output of the new help command was a bit too densely packed
for some commands.
Added missing values for the `alter server` command help output.
Adding a server to multiple monitors is forbidden. This should be detected
and reported to the end user.
The information provided by the config_runtime system to the client isn't
as detailed as it could be. Some sort of an error message stack should be
added so that client facing interfaces could properly report the reason
for the failure. Currently the only way to detect the reason of the
failure is to parse the log files.
The errors were detected but the code proceeded to call various functions
with bad pointers. This led to a crash if a bad server name was given to
'show server'.
The module commands operations are now listed as `commands` instead of
`functions`. The output was also formatted and an optional filtering was
added to the `list commands` call.
Maxadmin can now create and destroy monitors. The created monitors are not
started as they would be useless without added servers and configuration
parameters.
The code prevented scaling by imposing global spinlocks for the DCBs and
SESSIONs. Removing this list means that a thread-local list must be taken
into use to replace it.
The listeners aren't really destroyed and are only stopped. Further
changes are required so that they won't be started again once they have
been destroyed.
Maxadmin now supports the runtime creation of listeners. The new 'default'
value can be used to signal values that don't need to be configured and
the default value should be used.
The config_runtime.h header contains functions that can be used to
manipulate the running configuration. Currently the header contains the
function to create, add, remove and destroy servers.
The maxadmin interface to add servers to objects now allows a maximum of
11 objects to be listed. This will make it simpler to add a server to both
a monitor and a service in one command.
When a server is created in server_create, it sets the port to the default
of 3306 if no explicit port is defined. The code that called this function
still expected a minimum of three arguments: name, address and port.
When a service is added or removed from a service, a supplementary
configuration file is created. This allows MaxScale to survive restars and
unexpected downtime even if runtime changes to the servers of a service
have been made.
With these changes, it is possible to start MaxScale without any servers,
create servers, add the created servers to services and monitors and
restart Maxscale without losing the runtime configuration changes.
When a server is added to a monitor, an supplementary configuration file
is generated to persist this information. This will allow dynamic
modifications to server lists which will survive restarts and unexpected
downtime.
The monitor will only add new servers to its list of monitored
servers. This prevents duplicate entries in the list and makes it safe to
persist all used servers to the supplementary configuration file instead of only the ones that are not listed in the main configuration.
Servers created at runtime can now be configured to use SSL. The
configuration is only possible if the server is not in use.
The `alter server` command in maxadmin now takes a list of `key=value`
strings. This allows the user to define multiple alter operations with one
command.
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
