HPE Ezmeral Data Fabric Database Table Metrics

Starting in MapR 6.1, HPE Ezmeral Data Fabric Database supports table metrics. This section describes the available HPE Ezmeral Data Fabric Database table metrics. It also describes how to configure metrics per table, disable them in your cluster, and how to filter them by operation and table.

Table metrics are collected per node. By default, these metrics are written to OpenTSDB every minute. Pre-existing tables in your HPE Ezmeral Data Fabric cluster inherit this default setting. You can change this default per table using either the table create or table edit command. Secondary indexes inherit their metric configuration from their parent table.

You cannot disable metrics on individual tables. During installation, you can disable table metrics across your entire cluster. If you are using the installer, select the minimum metrics collection configuration option.

The following table lists HPE Ezmeral Data Fabric Database table metrics:
mapr.db.table.latency
The latency of RPC operations on tables, represented as a histogram. Endpoints identify histogram bucket boundaries.
Note: Put latency metrics for indexes reflect only the index update time. They do not include lag time due to asynchronous index updates.
mapr.db.table.read_bytes
The number of bytes read from tables.
mapr.db.table.read_rows
The number of rows read from tables.
mapr.db.table.resp_rows
The number of rows returned from tables.
mapr.db.table.rpcs
The number of RPC calls completed on tables.
mapr.db.table.value_cache_hits
The number of HPE Ezmeral Data Fabric Database operations on tables that utilized the HPE Ezmeral Data Fabric Database value cache.
mapr.db.table.value_cache_lookups
The number of HPE Ezmeral Data Fabric Database operations on tables that performed a lookup on the HPE Ezmeral Data Fabric Database value cache.
mapr.db.table.write_rows
The number of rows written to tables.
mapr.db.table.write_bytes
The number of bytes written to tables.

Tags for Table Metrics

Each table metric collects data across all operations on tables and secondary indexes in a HPE Ezmeral Data Fabric node. To view metrics for a particular RPC operation on a specific table, you must filter the metric by RPC type and table path, as described in the following list:
rpc_type

The name of the RPC:

  • append
  • check_and_put
  • get
  • increment
  • put
  • scan
  • update_and_get
table_path

The path of the HPE Ezmeral Data Fabric Database table.

OpenTSDB supports only the following characters:

  • Alphanumeric characters
  • Dot (.)
  • Underscore (_)
  • Dash (-)
  • Slash (/)
  • Space ( )
  • Unicode letters

If a table path contains characters that are not in this list, HPE Ezmeral Data Fabric cannot collect those table metrics.

index
The name of the secondary index defined on the table specified in table_path, if you want to filter on a specific index. When you specify this tag, you cannot specify the noindex tag.
Note: You can use regular expressions when specifying the index name to filter for a group of indexes.
noindex
Set to "//primary" if you want to filter metrics for only the primary table and exclude metrics for secondary indexes defined on the table. When you specify this tag, you cannot specify the index tag.
The following list shows examples of the table-specific tags to use to filter different table metrics:
mapr.db.table.write_rows
Tag Name: table_path
Tag Value: /var/mapr/mapr.monitoring/tsdb-meta
Description: The number of rows written to a table in the path /var/mapr/mapr.monitoring/tsdb-meta, including writes to its secondary indexes.
mapr.db.table.rpcs
    • Tag Name: rpc_type
    • Tag Value: get
    • Tag Name: table_path
    • Tag Value: /var/mapr/mapr.monitoring/tsdb-meta
    • Tag Name: noindex
    • Tag Value: //primary
Description: The number of completed get RPCs for a table in the path /var/mapr/mapr.monitoring/tsdb-meta, excluding metrics on the table's secondary indexes.
mapr.db.table.read_rows
    • Tag Name: table_path
    • Tag Value: /var/mapr/mapr.monitoring/tsdb-meta
    • Tag Name: index
    • Tag Value: tsdbIdx
Description: The number of rows read from a secondary index named tsdbIdx, defined on the table in the path /var/mapr/mapr.monitoring/tsdb-meta.
Note: In addition to these table-specific tags, Metric Collection describes other available tags.
Parent topic: HPE Ezmeral Data Fabric Database Metrics