ApiOmat provides monitoring capabilities at all layers. For most methods, a Nagios compatible monitoring system is required.

Checking the YAMBAS service

After running, each application server provides a specific healthcheck REST endpoint to check whether the service is alive (usable for load balancers, etc):

http(s)://YOURHOST/yambas/rest/health

The endpoint will respond with a HTTP statuscode 200, and a JSON object with status "UP" if the system is up and healthy. Otherwise it will respond with statuscode 503 and a JSON object with status "DOWN".

You can get detailed information about the health status by requesting the endpoint with SuperAdmin credentials. The endpoint will also provide additional health information, if the MongoDB is unavailable during server start or the SuperAdmin account does not exist.

{
    "mongo": {"status": "UP"},
    "hazelcast": {
        "localMemberSafe": true,
        "clusterSafe": true,
        "clusterState": "ACTIVE",
        "clusterSize": 1,
        "status": "UP"
    },
    "systemStartChecks": {
        "serverStarted": true,
        "jobSchedulerOk": true,
        "configOk": true,
        "superAdminDoesNotExist": false,
        "error": "",
        "licenseOk": true,
        "mongoOk": true,
        "status": "UP"
    },
    "jobScheduler": {
        "publicAllNodeScheduler": {
            "currentlyExecutingJobCount": 0,
            "started": true,
            "inStandby": false,
            "shutdown": false,
            "status": "UP"
        },
        "internalAllNodeScheduler": {
            "currentlyExecutingJobCount": 0,
            "started": true,
            "inStandby": false,
            "shutdown": false,
            "status": "UP"
        },
        "internalSingleNodeScheduler": {
            "currentlyExecutingJobCount": 0,
            "started": true,
            "inStandby": false,
            "shutdown": false,
            "status": "UP"
        },
        "publicSingleNodeScheduler": {
            "currentlyExecutingJobCount": 0,
            "started": true,
            "inStandby": false,
            "shutdown": false,
            "status": "UP"
        },
        "status": "UP"
    },
    "status": "UP"
}

Monitoring via ApiOmat Dashboard

Using the ApiOmat Dashboard to monitor your servers is an easy way to get an overview on different aspects of your servers like CPU and RAM usage.

To activate monitoring, install the Lurker service.

Checking the Apache Tomcat

The jolokia plugin monitors the status of the application container. Several parameters of a web application can be observed, like

track the number and rate of in coming requests per second
number of current connections

or common checks like memory and CPU usage of the whole Tomcat.

The plugin requires Jolokia and the agent plugin on the monitored server. Jolokia works with JMX.

Checking the MongoDB

MongoDB has its own Nagios/Check_MK plugin ( check_mk_active-mongodb) where e.g.

replication data
number of connections
current lock
database size

can be monitored.

Furthermore, mongo contains several command line tools to check performance and load: http://docs.mongodb.org/manual/administration/monitoring/

Configuration Details

Further configuration details to set up the monitoring service (e.g. running monitoring service on several nodes) are described within the article Configure Monitoring Extras.