Collect SQL Server Custom Metrics

This guide explains how to collect custom metrics from SQL Server.

Custom queries

To collect more complex custom metrics with the SQL Server integration, use the custom_queries option in the conf.d/sqlserver.d/conf.yaml file at the root of your Agent’s configuration directory. See the sample sqlserver.d/conf.yaml for more details.

Configuration

custom_queries has the following options:

OptionRequiredDescription
queryYesThe SQL to execute. This can be a simple statement or a multi-line script. All rows of the results are evaluated. Use the pipe character (|) if you require a multi-line script.
columnsYesA list representing each column ordered sequentially from left to right.

There are two required pieces of data:
- name: The suffix to append to the metric_prefix to form the full metric name. If the type is specified as tag, the column is instead applied as a tag to every metric collected by this query.
- type: The submission method (gauge, count, rate, etc.). This can also be set to tag to tag each metric in the row with the name and value (<name>:<row_value>) of the item in this column.
tagsNoA list of static tags to apply to each metric.
  • At least one of the items in defined columns should be a metric type (gauge, count, rate, etc.).

  • The number of items defined in columns must equal the number of columns returned in the query.

  • The order in which the items in columns are defined must be same order returned in the query.

    custom_queries:
      - query: Select F3, F2, F1 from Table;
        columns:
          - {name: f3_metric_alias, type: gauge}
          - {name: f2_tagkey      , type: tag  }
          - {name: f1_metric_alias, type: count}
        [...]
    

Example

Below is a company table from a testdb database. The table contains three employee records:

testdb=# SELECT * FROM company;

id| name  | age| address    |salary | entry_date | last_raise_time
-------------------------------------------------------------------
1 | Paul  | 32 | California | 20000 | 1457570000 | 1457570300
2 | Allen | 25 | Texas      | 30000 | 1457570060 | 1457570300
3 | Teddy | 23 | Norway     | 45000 | 1457570120 | 1457570300

The following SQL query captures the age and salary of Paul as metric values, with Paul’s name and address as tags.

SELECT age,salary,name,address FROM company WHERE name = 'Paul'

Corresponding custom_queries YAML configuration:

custom_queries:
  - query: SELECT age,salary,name,address FROM company WHERE name = 'Paul'
    columns:
      - name: employee_age
        type: gauge
      - name: employee_salary
        type: gauge
      - name: name
        type: tag
      - name: localisation
        type: tag
    tags:
      - 'query:custom'

After you update the SQL Server YAML file, restart the Datadog Agent.

Validation

To verify your results, search for the metrics using the Metrics Explorer.

Debugging

Run the Agent’s status subcommand and look for sqlserver under the Checks section:

sqlserver
--------
  - instance #0 [ERROR]: 'Missing query parameter in custom_queries'
  - Collected 0 metrics, 0 events & 0 service checks

Additionally, the Agent’s logs may provide useful information.

Collecting metrics from Performance Counters

By default, the Datadog-SQL server Check only captures some of the metrics available in the sys.dm_os_performance_counters table.

Find below an example for a basic metric collection from performance counters. Note: You can specify optional tags to be sent with your metrics:

custom_metrics:
  - name: sqlserver.clr.execution
    counter_name: CLR Execution
    tags:
      - tag_name:value

Parameter descriptions:

ParameterDescription
nameName of your metric inside Datadog.
counter_nameThe counter name of SQL server database objects.
tagsA list of key:value tag pairs.

If a counter has multiple instances associated with it, you can choose to fetch a single instance with the instance_name parameter name:

custom_metrics:
  - name: sqlserver.exec.in_progress
    counter_name: OLEDB calls
    instance_name: Cumulative execution time (ms) per second

For finer granularity, query by the object_name :

custom_metrics:
- name: sqlserver.cache.hit_ratio
  counter_name: Cache Hit Ratio
  instance_name: SQL Plans
  object_name: SQLServer:Plan Cache

To collect all instances of a counter with multiple instances, use the special, case-sensitive value ALL for the instance_name parameter which requires a value for the tag_by parameter. This example gets metrics tagged as db:mydb1, db:mydb2:

custom_metrics:
  - name: sqlserver.db.commit_table_entries
    counter_name: Commit table entries
    instance_name: ALL
    tag_by: db

The default table from which counters are drawn is the sys.dm_os_performance_counters table. The Datadog-SQL Server check also supports sys.dm_os_wait_stats, sys.dm_os_memory_clerks, and sys.dm_io_virtual_file_stats.

To report a metric drawn from one of the additional tables, specify the table in the counter definition with the table parameter, as well as the counter columns to be reported with the columns parameter:

custom_metrics:
  - name: sqlserver.LCK_M_S
    table: sys.dm_os_wait_stats
    counter_name: LCK_M_S
    columns:
      - max_wait_time_ms
      - signal_wait_time_ms

The above example reports two metrics, sqlserver.LCK_M_S.max_wait_time.ms and sqlserver.LCK_M_S.signal_wait_time_ms.

Note: If metrics like sys.dm_io_virtual_file_stats and sys.dm_os_memory_clerks are not associated with a counter_name only the columns need to be specified:

custom_metrics:
  - name: sqlserver.io_file_stats
    table: sys.dm_io_virtual_file_stats
    columns:
      - num_of_reads
      - num_of_writes

The above example reports two metrics, sqlserver.io_file_stats.num_of_reads and sqlserver.io_file_stats.num_of_writes each tagged with the database ID and file ID.

Collecting metrics from a custom procedure (legacy)

This is a legacy method of collecting custom metrics from the database. It is recommended to use the custom_queries parameter, which requires less setup, provides more flexibility in the types of T-SQL that can be executed, and is easier to debug. Collecting metrics from a custom procedure produces a large volume of custom metrics that may affect your billing.

Setup a stored procedure

You must set up a temporary table to collect the custom metrics for reporting to Datadog. The table needs the following columns:

ColumnDescription
metricThe name of the metric as it appears in Datadog.
typeThe metric type (gauge, rate, or histogram).
valueThe value of the metric (must be convertible to a float).
tagsThe tags that appear in Datadog separated by a comma.

The following stored procedure is created within the master database:

-- Create a stored procedure with the name <PROCEDURE_NAME>
CREATE PROCEDURE [dbo].[<PROCEDURE_NAME>]
AS
BEGIN

  -- Create a temporary table
  CREATE TABLE #DataDog
  (
    [metric] varchar(255) not null,
    [type] varchar(50) not null,
    [value] float not null,
    [tags] varchar(255)
  )

  -- Remove row counts from result sets
  SET NOCOUNT ON;

  -- Create variable count and set it equal to the number of User Connections
  DECLARE @count float;
  SET @count = (select cntr_value from sys.dm_os_performance_counters where counter_name = 'User Connections');

  -- Insert any custom metrics into the table #Datadog
  INSERT INTO #Datadog (metric, type, value, tags)
  VALUES ('sql.test.test', 'gauge', @count, 'db:master,env:staging')
        ,('sql.test.gauge', 'gauge', FLOOR(RAND()*20), 'tag:test')
        ,('sql.test.rate', 'rate', FLOOR(RAND()*20), 'metric:gauge')
        ,('sql.test.histogram', 'histogram', FLOOR(RAND()*20), 'metric:histogram')
  SELECT * from #DataDog
END
GO

-- Grant permission to run the stored procedure
GRANT EXECUTE ON [dbo].[<PROCEDURE_NAME>] To Public
GO

The stored procedure outputs the following custom metrics:

  • sql.test.test
  • sql.test.gauge
  • sql.test.rate
  • sql.test.histogram.95percentile
  • sql.test.histogram.avg
  • sql.test.histogram.count
  • sql.test.histogram.max
  • sql.test.histogram.median

Update the SQL Server integration configuration

To collect metrics from a custom procedure, create a new instance definition inside your sqlserver.d/conf.yaml file with the procedure to execute. A separate instance is required for any existing configuration. Instances with a stored procedure do not process anything but the stored procedure, for example:

  - host: 127.0.0.1,1433
    username: datadog
    password: "<PASSWORD>"
    database: master
  - host: 127.0.0.1,1433
    username: datadog
    password: "<PASSWORD>"
    stored_procedure: "<PROCEDURE_NAME>"
    database: master

You can also specify:

ParameterDescriptionDefault
ignore_missing_databaseIf the DB specified doesn’t exist on the server, then don’t do the check.False
proc_only_ifRun this SQL before each call to stored_procedure. If it returns 1, call the procedure.
proc_only_if_databaseThe database to run the proc_only_if SQL in.database attribute

Note: The proc_only_if guard condition is useful for high-availability scenarios where a database can move between servers.

Troubleshooting

If your custom metrics do not appear in Datadog, check the Agent log file. If you see the following error: Could not call procedure <PROCEDURE_NAME>: You must supply -1 parameters for this stored procedure, it could be one of the following issues:

  • The <PROCEDURE_NAME> is typed incorrectly.
  • The database username specified in the configuration may not have permission to run the stored procedure.

Further Reading

Additional helpful documentation, links, and articles:

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