Network Management

Decrease NCM CacheDiffResults table

The NCM_CacheDiffResults or NCM_ConfigArchive table in the Orion Database has been noted as being large and maybe impacting NCM or Orion performance.

First published date

10/22/2018 2:53 PM

Last published date

2/14/2023 12:46 PM

Overview

The NCM CacheDiffResults  or NCM ConfigArchive table in the Orion Database has been noted as being large and maybe impacting NCM or Orion performance in general. This article provides steps to trim it down. NCM has a job set up for the routine cleaning of tables in the database as well as the Config Archive folder on the NCM server.

Example of large NCM tables scenario:
Number of records in ncm_configarchive (1536020) / ncm_nodeproperties (4360) = 352

You will have to reduce this Number, over 350 Configs per Node is not realistic. As it will have a negative impact on overall Orion Performance due to the size of the tables. A value of 30-60 on average is ok

It is generally recommended to keep it for three months or less be maintained in the database.(30 to 60 configs if only saving configs if they changed)

Product section

Network Configuration Manager

Cause

  • Large NCMConfigArchive or NCMCacheDiffResults tables in DB

Resolution

NCM has a job set up for the routine cleaning of tables in the database as well as the Config Archive folder on the NCM server.

  1. From the Web Console, go to NCM jobs.
  2. Select Job "Default Database and Archive Maintenance", and then click Edit.
  3. Set the Frequency of the job to run, (generally, weekly is sufficient), and then click Next.
  4. There are no options to select on Choose Nodes section, and then click Next.
  5. Notifications and logging page at your discretion, and then click Next.
  6. Add Job Specific Details. This is the core of the job: purge configs from the config archive folder older than xx.
    1. Generally, you can un-check this unless space is becoming an issue, but if it is, recommend to back up and move these to store for disaster recovery, before deleting regardless.
    2. The location is determined by the settings > NCM settings > Config Archive Folder Locations.
    3. These are the device configurations downloaded to the Server and not the database.
    4. Purge config cache data older that:  XX
      1. Generally, Resources are maintained at as of last update, but could be looking over a specified period of time. Use this as well as the frequency of how often devices are backed up and what type of configs you are backing up. Three months is a general rule of thumb for the data retention here, but the value is up to the the user and the policies in place as have these on a view.
      2. Each time a config is downloaded, it will compare to the same config type, then each of the others and then write an entry for each in the table, per config per device.
      3. This data is what is used to populate the Charts regarding the Config Differences (Running, Run vs start, Run vs Baseline.
    5. Purge Job Log:  These logs can be purged frequently and default settings should be sufficient.
    6. Purge Config Transfer request older than XX
      1. The size of this table is dependent on manual operations such as download configs, execute scripts via NCM.  Actions performed by jobs will not impact this table.
      2. the size of this table can impact the operations of these manual tasks if the table gets large, but is a good place to look for troubleshooting or validating work.