Replication Monitoring is a tool that will allow users to monitor the status and progress of data being replicated by the Event Replicator for Adabas. While statistical information (metrics) may be gathered by issuing DRPLSTAT operator commands, utilizing the Replication Monitoring tool provides an automated way to collect these metrics. The metrics may then be graphically viewed using the Kibana application. Kibana, along with ElasticSearch analytics engine, may be installed under a Windows, UNIX or Linux operating system.

Activating the Replication Monitoring subsystem is achieved by setting the value of the global variable parameter, STATINTERVAL, to a value other than zero. A new Destination, with a destination type (DTYPE) of ETBROKER or MQSERIES (or NULL for test purposes), should then be created, and the DSTATLOG parameter set to "YES". The result of setting up this new Destination will be for the Replication metrics to be sent to the Adabas Analytics component of Replication Monitoring.

One additional parameter is the DEVENTLOG. Setting this to "YES" will result in events to be sent to the Adabas Analytics component. Examples of events include Destination(s) being Opened or Closed, or Subscription File(s) being Activated and Deactivated.

Another aspect of Replication Monitoring is the Heartbeat feature. There is one new parameter that needs to be set to activate this feature: DHBINTERVAL. The DHBINTERVAL determines how often the Event Replicator Server sends a heartbeat to a Destination. The Destination must be one used to send replication data to the Event Replicator Target Adapter.

Using Kibana, it is possible to visualize a number of metrics provided by the Event Replicator Server. Each visualization may be of a single or multiple metrics, or a customized dashboard may be created to have a single view of a number of visualizations. Then, with the flexibility of ElasticSearch, the dashboards may facilitate different time ranges of metrics; as much as one year, showing a view of the replication workload trends.

The Replication metrics have a number of categories, which are described in more detail in the section Replication Monitoring Metrics. The categories are as follows:

• Global General Statistics
  This provides an overview about the number of transactions received and sent by the Event Replicator Server.

• Subscription
  Where a number of Subscriptions may have been defined to the Event Replicator Server, an overview of the activities of any/all subscriptions may be monitored. This includes any Replication Initial State requests (i.e. Initial State requests not done asynchronously using the ADARIS utility).

• Subscription file
  For each Subscription, one or more Subscription files may be defined. Monitoring these provides details about the commands being issued for each file.

• Destination
  Monitoring the Destinations provides an overview of the number of items being sent to specific targets and the amount of data. If Destination is manually or automatically closed, and logging is active, the amount of data being logged and de-logged may be tracked, i.e. Destination SLOGing activities are.

• Destination file for an Adabas destination
  Where the Replication is from Adabas to Adabas. the modifications being made to the target destination files may be tracked.

• Subtask
  Where the Destination types are either EntireX Broker or MQ Series, an overview of the replicated transactions may be monitored.

• Input queue
  If Node to Node Replication is being used or other requests are being sent by an application to the Event Replicator Server, these may be monitored.

• SLOG
  Under general statistics, the usage of the SLOG system file may be monitored. The number of items logged and de-logged from the file may be tracked.

• Events
  When Replication is active, a number of events may occur during normal processing, e.g. a Destination may become closed or opened, a file may be inactive or active, a destination may become full, the Replication Pool may become short on storage. These events would be written to the console but, with Replication Monitoring, a specific visualization allows an overview of all events to be viewed.

• Event Replicator Target Adapter (ART)
  The Event Replicator Target Adapter subsystem activities may, similarly, be tracked. There are a number of java beans that Event Replicator Target Adapter provides to monitor replicated transactions being processed. This will be done for each target (e.g. RDBMS, JMS, Terracotta). These metrics will also be viewable from Kibana, showing visualizations of the trends or current status of Event Replicator Target Adapter. See also Reviewing Event Replicator Target Adapter Statistics for further details.

• Heartbeat
  When the Heartbeat feature is active, the heartbeats sent to the Event Replicator Target Adapter, will have various timestamps. These timestamps will reflect the latency at various points; points that would indicate if the delivery of the replicated data is being delayed. Examples would be, if the workload being sent to the Event Replicator Server and the data had to be written to the SLOG, or if it was queued up in the EntireX Broker or MQ Series.

  Once the heartbeat reaches the Event Replicator Target Adapter, additional information is added before the heartbeat metrics are passed on to the Adabas Analytics component. In short, the heartbeat will provide information that reflects the rate at which replicated data is being processed and is likely to change based on the number of transactions being replicated.

  See also Reviewing Event Replicator Target Adapter Statistics for further details.