Table of Contents

Specifying TTL overrides

The "time to live" (TTL) determines how long specific data is retained before being automatically removed from your DataMiner System. By setting TTL overrides, you can control the lifespan of various data types, such as real-time trending, minute trending, and alarm events. Some data types, such as elements, do not have a TTL and never expire.

This page explains how to configure TTL settings to optimize your database performance and resource utilization.

Note

If a DMS uses Storage as a Service, the default TTL is automatically applied for most database records. The configuration in Cube is only taken into account for real-time trending.

In System Center, you can configure a custom TTL for data in the database. This determines how long the data is kept in the database.

  1. In DataMiner Cube, go to System Center > System settings > time to live.

  2. To configure general TTL overrides:

    1. Specify the necessary override values in the DMS defaults section.

      • If your system has an Indexing database, the Local column contains TTL settings for the Cassandra general database, and the Indexing column contains TTL settings for the Indexing database.

      • At present, trending information is not saved in the indexing database. As such, if your DMS uses an indexing database, only the settings in the Local column of the time to live page will be taken into account for trending.

      • The Alarm events setting applies both for alarms and information events.

    2. Click Apply.

  3. To configure TTL overrides for the trend data of a specific protocol or protocol version:

    1. In the Overrides section, click Add.

    2. In the pop-up window, select a protocol and if necessary a protocol version, and click Add.

    3. In the Trending section on the right, specify the necessary override values in the boxes for the various records.

    4. Click Apply.

The following default values and limitations apply:

Type of data Default TTL Minimum TTL Maximum TTL
Real-time trending 1 day 15 minutes 1098 days
Minute trending 31 days 1 hour 1098 days
Hour trending 366 days 12 hours 1830 days
Day trending 0 seconds 15 days 12 hours 3660 days
Alarm events 366 days 1 hour 3660 days
History slider 31 days 1 hour 3660 days
Spectrum traces 366 days 1 hour 3660 days
Note
  • The TTL settings are stored in the file DBMaintenanceDMS.xml. For more information, see DBMaintenance.xml and DBMaintenanceDMS.xml.
  • If a record is saved with a particular TTL setting in a Cassandra database, this setting applies permanently for that record, even if the configuration is later changed in Cube. The changes are only applied for new records. For example, if a record is saved with TTL set to 150 days, it will only be removed after 150 days, even if the TTL configuration in Cube is later changed to 100 days.
  • To prevent the year 2038 problem for Cassandra, from DataMiner 10.2.0 [CU14]/10.3.0 [CU2]/10.3.4 onwards, the maximum allowed TTL for databases is limited to 10 years.
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