Applies To: SQL Server 2014, SQL Server 2016 Preview
Captures diagnostic data and health information about SQL Server to detect potential failures. The procedure runs in repeat mode and sends results periodically. It can be invoked from either a regular or a DAC connection.
Applies to: SQL Server (SQL Server 2012 through current version).
- [ @repeat_interval =] ' repeat_interval_in_seconds '
Indicates the time interval at which the stored procedure will run repeatedly to send health information.
repeat_interval_in_seconds is int with the default of 0. The valid parameter values are 0, or any value equal to or more than 5. The stored procedure has to run at least 5 seconds to return complete data. The minimum value for the stored procedure to run in the repeat mode is 5 seconds.
If this parameter is not specified, or if the specified value is 0, the stored procedure will return data one time and then exit.
If the specified value is less than the minimum value, it will raise an error and return nothing.
If the specified value is equal to or more than 5, the stored procedure runs repeatedly to return the health state until it is manually canceled.
0 (success) or 1 (failure)
sp_server_diagnostics returns the following information
Indicates the time stamp of row creation. Each row in a single rowset has the same time stamp.
Indicates whether the row contains information for the SQL Server instance level component or for an AlwaysOn availability group:
Indicates the name of component or the name of the availability group:
Indicates the health status of the component:
Describes the state column. Descriptions that correspond to the values in the state column are:
Specifies data that is specific to the component.
Here are the descriptions of the five components:
system: Collects data from a system perspective on spinlocks, severe processing conditions, non-yielding tasks, page faults, and CPU usage. This information is produces an overall health state recommendation.
resource: Collects data from a resource perspective on physical and virtual memory, buffer pools, pages, cache and other memory objects. This information produces an overall health state recommendation.
query_processing: Collects data from a query-processing perspective on the worker threads, tasks, wait types, CPU intensive sessions, and blocking tasks. This information produces an overall health state recommendation.
io_subsystem: Collects data on IO. In addition to diagnostic data, this component produces a clean healthy or warning health state only for an IO subsystem.
events: Collects data and surfaces through the stored procedure on the errors and events of interest recorded by the server, including details about ring buffer exceptions, ring buffer events about memory broker, out of memory, scheduler monitor, buffer pool, spinlocks, security, and connectivity . Events will always show 0 as the state.
<name of the availability group>: Collects data for the specified availability group (if component_type = "alwaysOn:AvailabilityGroup").
From a failure perspective, the system, resource, and query_processing components will be leveraged for failure detection while the io_subsystem and events components will be leveraged for diagnostic purposes only.
The following table maps the components to their associated health states.
The (x) in each row represents valid health states for the component. For example, io_subsystem will either show as clean or warning. It will not show the error states.
Requires VIEW SERVER STATE permission on the server.
It is best practice to use the extended sessions to capture the health information and save it to a file that is located outside of SQL Server. Therefore, you can still access it if there is a failure. The following example saves the output from an event session to a file:
CREATE EVENT SESSION [diag] ON SERVER ADD EVENT [sp_server_diagnostics_component_result] (set collect_data=1) ADD TARGET [asynchronous_file_target] (set filename='c:\temp\diag.xel'); GO ALTER EVENT SESSION [diag] ON SERVER STATE = start; GO
The example query below reads the extended session log file:
SELECT xml_data.value('(/event/@name)','varchar(max)') AS Name , xml_data.value('(/event/@package)', 'varchar(max)') AS Package , xml_data.value('(/event/@timestamp)', 'datetime') AS 'Time' , xml_data.value('(/event/data[@name=''component_type'']/value)','sysname') AS Sysname , xml_data.value('(/event/data[@name=''component_name'']/value)','sysname') AS Component , xml_data.value('(/event/data[@name=''state'']/value)','int') AS State , xml_data.value('(/event/data[@name=''state_desc'']/value)','sysname') AS State_desc , xml_data.query('(/event/data[@name="data"]/value/*)') AS Data FROM ( SELECT object_name as event ,CONVERT(xml, event_data) as xml_data FROM sys.fn_xe_file_target_read_file('C:\Program Files\Microsoft SQL Server\MSSQL13.MSSQLSERVER\MSSQL\Log\*.xel', NULL, NULL, NULL) ) AS XEventData ORDER BY time;
The following example captures the output of sp_server_diagnostics to a table in a non-repeat mode:
CREATE TABLE SpServerDiagnosticsResult ( create_time DateTime, component_type sysname, component_name sysname, state int, state_desc sysname, data nvarchar(max) ); INSERT INTO SpServerDiagnosticsResult ; EXEC sp_server_diagnostics;