The parameter names for monitors and servers now use a set of constant
names. This removes some of the errors caused by spelling mistakes when
the same parameter name is repeated in multiple places.
The service, filter and listener parameters should also be converted to
constants. This allows for a consistent user experience.
The relationships from servers to services and monitors and filters to
services were not implemented. Now each server lists the services and
monitors that use it and each filter lists the services that use the
filter.
This enables the creation of a server and linking of that server to
services and monitors in one atomic operation.
When a resource has a relation to another resource, it should be expressed
as a working link to the resource. By passing the hostname of the server
to the functions, we are able to generate working relation links.
The modules that implement a diagnostics entry point now return a JSON
type object. This removes the need to format data inside the modules.
The module implementations of these are not yet complete which means that
MaxScale will fail to compile.
Monitors can now be printed in JSON format. The REST API resource
`/monitors` accepts GET requests and returns a JSON representation of the
monitors as a response.
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.
Moved some typedefs to router.h and server.h, changed a few
constants to these enums. Renamed some types in config.h to
remove "Gateway".
There are still some functions in the public header which are
only used in core, but they seem to fit the theme of public functions
so were not moved.
This removes parts of the nearly identical code from all monitors.
The removal of monitor type specific event checking is done based on the
assumption that only the monitor that is monitoring the server can be the
cause for a state change. This removes the need to actually check that the
state change is relevant for each monitor and allows the event handling to
be moved into the core.
Previously, server status changes from MaxAdmin would be set immediately
as long as the server lock could be acquired. This meant that it might take
several seconds until the next monitor pass is executed. Usually, this was
fine but in some situations we would want the monitor to run immediately
after the change (MXS-740 and Galera). This patch changes the logic of
setting and clearing status bits to a delayed mode: changes are first applied
to a "status_pending"-variable, and only once the monitor runs will the
setting be applied. To reduce the delay, the monitor now has a flag
which is checked during sleep (between short 0.1s naps). If set, the
sleep is cut short.
If a server is not monitored, the status bits are set directly.
There is a small possibility of a race condition: If a monitor is stopped or
destroyed before the pending change is applied, the change is forgotten.
MXS-873 To prevent monitors and MaxAdmin from interfering with each other,
changes to the server status flags now happen under a lock. To avoid
interfering with monitor logic, the monitors now acquire locks to all
of their servers at the start of the monitor loop and release them
before sleeping.
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 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.
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.
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
- All now include maxscale/cdefs.h as the very first file.
- MXS_[BEGIN|END]_DECLS added to all C-headers.
Strictly speaking not necessary for private headers, but
does not hurt either.
- Include guards moved to the very top of the file.
- #pragma once added.
- Headers now to be included as <maxscale/xyz.h>
- First step, no cleanup of headers has been made. Only moving
from one place to another + necessary modifications.
