Configuration of MongoTransTest

Using the MongoTransTest test, administrators can be instantly alerted if more than a permissible number of rollbacks are happening on a target MongoDB server. In addition, the test monitors transaction checkpoints. A checkpoint acts as a recovery point for an operation. When a transaction attempts to modify the data in a data file, MongoDB presents an in-memory snapshot/copy of that data and allows changes to be made to that data. While writing the data in the snapshots to the disk, MongoDB creates restoration points between the snapshots, called checkpoints. If these checkpoints are not created frequently, it only means that data is not written to the disk regularly; this increases the risk of data loss during recovery. To avoid this, administrators can use the MongoTransTest test to monitor the time taken for creating the most recent checkpoint and thus, quickly detect delays in check point creation or writing to disk.

The default parameters associated with this test are as follows:

• The TEST PERIOD list box helps the user to decide how often this test needs to be executed.

• In the HOST text box, specify the IP address of the Mongo database server for which this test is to be configured.

• In the PORT text box, specify the port number through which the Mongo database server communicates. By default, this is 27107.

• The test connects to a specific Mongo database to run API commands and pull metrics of interest. Specify the name of this database in the DATABASE NAME text box. The default value of this parameter is admin.

• If multiple components of the same component type are awaiting configuration, then an APPLY TO OTHER COMPONENTS check box will appear in this page. Clicking on this check box will allow you to apply the configuration to all/selected components of that type.

• Once the necessary values have been provided, clicking on the UPDATE button will register the changes made.

When changing the configuration for specific servers, a “*” beside the text box corresponding to the parameter signifies that these values have to be manually configured by the user. The parameter values that require to be configured will typically be prefixed with a “$“ or contain a series of “*”. A value of "none" in the parameter value indicates that the corresponding parameter value can be changed if required.