Can "Monit" monitor the processes running on remote servers? - nginx

Question

I want to setup monit on a server which is going to be a centralized server to monitor processes running on remote servers. I checked many docs related to setup monit but could not find how to setup for remote server processes. For example a centralized monit server should monitor nginx running on A server, mongod running on B server and so on. Any suggestion how to do this?

Answer 1

In the documentation, Monit can be able to test the connection remotely, using tcp or udp, what you can do is to provide a small status file that gets refreshed for each technology you are intending to monitor, and let Monit hit that status file through http, etc. and can be used as follows:
check host nginxserver with address www.nginxserver.com
if failed port 80 protocol http
and request "/some_file"
then alert
Since you are testing a web server that can be easily accomplished with the above. as a note , below is the part about Monit connection testing:
CONNECTION TESTING Monit is able to perform connection testing via
networked ports or via Unix sockets. A connection test may only be
used within a check process or within a check host service entry in
the Monit control file.
If a service listens on one or more sockets, Monit can connect to the
port (using either tcp or udp) and verify that the service will accept
a connection and that it is possible to write and read from the
socket. If a connection is not accepted or if there is a problem with
socket i/o, Monit will assume that something is wrong and execute a
specified action. If Monit is compiled with openssl, then ssl based
network services can also be tested.
The full syntax for the statement used for connection testing is as
follows (keywords are in capital and optional statements in
[brackets]),
IF FAILED [host] port [type] [protocol|{send/expect}+] [timeout]
[retry] [[] CYCLES] THEN action [ELSE IF SUCCEEDED [[]
CYCLES] THEN action]
or for Unix sockets,
IF FAILED [unixsocket] [type] [protocol|{send/expect}+] [timeout]
[retry] [[] CYCLES] THEN action [ELSE IF SUCCEEDED [[]
CYCLES] THEN action]
host:HOST hostname. Optionally specify the host to connect to. If the
host is not given then localhost is assumed if this test is used
inside a process entry. If this test was used inside a remote host
entry then the entry's remote host is assumed. Although host is
intended for testing name based virtual host in a HTTP server running
on local or remote host, it does allow the connection statement to be
used to test a server running on another machine. This may be useful;
For instance if you use Apache httpd as a front-end and an
application-server as the back-end running on another machine, this
statement may be used to test that the back-end server is running and
if not raise an alert.
port:PORT number. The port number to connect to
unixsocket:UNIXSOCKET PATH. Specifies the path to a Unix socket.
Servers based on Unix sockets always run on the local machine and do
not use a port.