MapR Database Table Metrics

Starting in MapR 6.1, MapR Database supports table metrics. This section describes the available MapR 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 MapR 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 MapR installer, select the minimum metrics collection configuration option. If you are doing a manual install, see Installing Metering Using Manual Steps.

The following table lists MapR Database table metrics:

Name Description
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 MapR Database operations on tables that utilized the MapR Database value cache
mapr.db.table.value_cache_lookups The number of MapR Database operations on tables that performed a lookup on the MapR 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 MapR 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 table:

Tag Name Description

The name of the RPC:

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

The path of the MapR 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, MapR 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 table shows examples of the table-specific tags to use to filter different table metrics:

Desired Metric Metric Name Tag Name Tag Value
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.write_rows table_path /var/mapr/mapr.monitoring/tsdb-meta
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.rpcs rpc_type get
table_path /var/mapr/mapr.monitoring/tsdb-meta
noindex //primary
The number of rows read from a secondary index named tsdbIdx, defined on the table in the path /var/mapr/mapr.monitoring/tsdb-meta mapr.db.table.read_rows table_path /var/mapr/mapr.monitoring/tsdb-meta
index tsdbIdx
Note: In addition to these table-specific tags, Metric Collection describes other available tags.