This documentation supports the 20.02 version of BMC CMDB.

To view an earlier version, select the version from the Product version menu.

Reconciliation best practices

For reconciliation to be effective, you must be aware of the following best practices. You must follow some of these guidelines to prepare your data, and follow other guidelines throughout the process. 


Related topics

Reconciliation issues

Creating and editing a dataset

BMC Community blog about Helix Support Focus on CMDB Reconciliation Open link

Watch the following video about configuring reconciliation jobs for better performance:

https://youtu.be/nbhq8Zbny9g

Import data sets

Make sure that each data provider has its own import data set.

CI attributes

Verify that the CI (configuration item) attributes used in the identification rules of identify activity have unique values and are populated consistently. 

If you use a standard job with the standard identification rules, you can verify the classes and identifying attributes on the Standards tab in Configurations > Manage Reconciliation Rules > Identification Rules

Example

The Name attribute is used to identify instances of most classes, but for some classes the identification rules include other attributes. The standard rules identify instances of BMC_DiskDrive are based on Name and SerialNumber.


Warning

Do not populate the TokenID attribute unless you know the formulae that BMC Discovery products use to populate it. The Token ID is reserved for use by some BMC discovery applications and is one of the primary attributes for identifying a computer system.

The identify activity and reconciliation IDs

To set up a reconciliation job, you must configure identification activities that match instances across datasets. The Identify activity reviews all incoming data, determines similar CIs across more than one data set, and marks where these data set instances seem to be the same CI. 

The reconciliation engine marks CI and relationship instances with reconciliation IDs that are unique to individual CIs within a data set. 

This initial marking step is critical to enable the compare and merge activities without causing conflicts from overlapping data that could potentially corrupt your CMDB with unreliable CI data.

Warning

Do not change the value of the ReconciliationIdentity attribute for unidentified and identified CIs or relationships.

Changing the value of the ReconciliationIdentity attribute for unidentified and identified CIs or relationships to some other character causes inconsistent results. The reconciliation engine looks for a value of 0 for unidentified CIs in the ReconciliationIdentity attribute.

The reconciliation ID is stored in the ReconciliationIdentity attribute of the BMC_BaseElement and BMC_BaseRelationship classes. 
In CMDB Portal, you can use the following setting to modify the reconciliation ID at Jobs > Manage Reconciliation > Create Job >  Add Activity > Identify.

 

If this option is enabled, the reconciliation engine searches for CIs in the production data set that have a reconciliation ID of 0 and sets the ID to a non-zero value that is unique across all data sets.

Reconciliation in a server group

In response to server status changes, the reconciliation engine automatically executes reconciliation jobs on a primary or secondary server in a server group. A server group is two or more servers that share the same database and provide failover operations.

The Remedy AR System server notifies the reconciliation engine for a status change. If the primary server status changes to suspended, the reconciliation engine stops reconciliation jobs on the primary server and resumes them on another server from the point where it stopped on the primary server. If the primary server status changes to running, reconciliation jobs on secondary servers are paused and resumed on the primary server.

The reconciliation engine assigns the SGPaused status when a job is paused while the job switches from one server to another in the server group. For example, when a job is running on one server (server 2) and a higher ranking server (server 1) comes up, the reconciliation engine pauses the job on server 2 and updates the job run status to SGPaused.

Tips

Not applicable to BMC Helix Subscribers because Helix environments are already configured according to the best practices.

  • To exclude a server that has no rank assigned or a user facing server from running reconciliation jobs, comment out the reconciliation engine entry (arrecond.exe) in the armonitor.cfg file.
  • To exclude a ranked server from running reconciliation jobs, remove rank of the server and comment out the reconciliation engine entry (arrecond.exe) in the armonitor.cfg file.

The Remedy AR System server transfers control from one server to another depending on the Rank value specified in the Remedy AR System group operation ranking form. The reconciliation engine requires three iterations of 60 seconds each (180 seconds total) to transfer a job from one server to another so that the first server properly pauses the running jobs and the second server resumes the jobs. This process avoids running the same job on both servers simultaneously.

For more information about Remedy AR System and server groups, see the  Action Request System documentation Open link  .


When you configure reconciliation, consider the following recommendations:

  • Do not rename the out-of-the-box reconciliation jobs, because other products could be using the default names given to those jobs.
  • After discovering data, normalize the data, and reconcile it into your production data set immediately after your discovery application loads data into BMC CMDB.
  • Do not create jobs that simultaneously identify the same data set or merge data into the same target data set. Simultaneous reconciliation can either overwrite data you wanted to keep from the other job or create duplicate CI instances.
  • If you need to create multiple jobs to merge data into the same production data set, use the Execute activity to run the jobs sequentially or set the jobs as continuous and run them in parallel by selecting the View Other Datasets for Parallel Continuous Jobs option. You can configure this option from Configurations > Core Configurations > Reconciliation.
  • Always perform the identify activity against the source datasets and never against the production datasets. The production dataset is the result of the reconciliation activities. Do not specify the production dataset as a source dataset while performing the identify activity because the CIs in the production dataset are already identified. The following image shows the field to select the source dataset:
  • Use a standard identification and a merge job, if possible.
  • Test with a small amount of representative data by using a qualification.
  • Do not run during prime (heavy use) hours.
  • (Not applicable for BMC Helix Subscribers) Consider indexing attributes used in Identify rules. Consult your database administrator to determine what indexes would help you.
  • Create all your reconciliation definitions at the highest class level possible to take advantage of inheritance.
  • After the initial data load into BMC CMDB, perform an Identify activity on the data, selecting the option to auto-identify the master dataset. This makes sure that your production data has an identity the first time it is identified against another dataset.
  • Take advantage of Reconciliation Engine multithreading by breaking up large jobs into smaller ones and running them concurrently, but limit your number of concurrent threads to twice the number of CPUs in the server.
  • (Not applicable for BMC Helix Subscribers) To improve performance, define a private queue on the Remedy AR System serverfor use only by the Reconciliation Engine. Make sure you use RPC socket 390698 or 390699.
  • Regularly review your Identify rules to make sure that they are still appropriate for your environment, and spot-check instances to confirm that they are being identified correctly.
  • Instead of merging multiple discovery sources directly into your production dataset, merge them into a "consolidated discovery" dataset first. You can compare this against your production dataset and use the results to generate change requests or exception reports for any discrepancies.
  • Do not run more than one Atrium Integrator, Normalization Engine, and Reconciliation Engine jobs at the same time because they might query or update the same data and might have an impact on system resource availability.
  • Run the reconciliation jobs in a sequence.
  • Avoid running multiple jobs in parallel. If you must run the jobs in parallel, make sure that one job is a batch job and the other one is a continuous job.
  • For a large amount of data, such as an initial load, run separate identify and merge jobs to allow for better diagnostics.
  • For incremental updates, run identify and merge activities in one job. For new CIs, the identify and merge activities may take more time to run. For modified CIs, the identify activity runs quickly because the CIs have reconciliation IDs.
  • In a reconciliation job, the Identify and Merge activities are run sequentially, based on the Sequence ID given in the reconciliation job which means that the instances start merging into the target data set only after all instances are identified. For a large amount of data, you can create separate identify and merge jobs and configure the merge job to run in a continuous mode. When the continuous merge job runs at the specified interval, all identified instances with the  ReconciliationMergeStatus attribute set to Ready to Merge are merged into the target data set. This configuration ensures that identified instances can begin merging into the target data set while the Identify activity is still running on the remaining unidentified instances.

    • When you make customizations, for example, add filters to the out-of-the-box job forms, if you face issues with the performance for these customizations, check the server-side AR API, SQL, and Filter logs. You can access the logs from AR System Management Console > AR System Server Group Console > Logs > View Logs as shown in the following figure:
    • For issues that occur when you run Reconciliation or Atrium Integrator jobs, for example, jobs that are stuck or reconciliation jobs are queued for a long time, verify the information in the respective job logs and take necessary action. You can view the logs in the following locations:

      Reconciliation logs(Windows)<AR System installation directory><\ARSystem\Arserver\Db\re>
      (UNIX)<AR System installation directory></ARSystem/db/re>
      Atrium integrator logs(Windows) <AR System installation directory><\ARSystem\Arserver\Db> (UNIX) <AR System installation directory></ARSystem/db>

      Important

      If you are BMC Helix Subscriber, you can access the logs in the View Logs page in AR System Management Console. For accessing any other logs, contact BMC Support.

    • Make sure that your QA environment is same as the production environment in terms of volume of data and configurations.
    • If you change any settings, or make customizations, test the changes in the QA environment. Only after you consistently get the expected results, promote the changes to the production environment.


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