Recently I needed to create a process to monitor performance counters over a short period of time. We were going to implement a change and we wanted to compare performance before and after to see if there was any impact.
To do this, I first created a couple of tables. One table is used to actually store the monitored values. The second table is used for configuration; you insert only the counters you want to monitor.
/* Create the table to store our logged perfmon counters */ Create Table dbo.dba_perfCounterMonitor ( capture_id int Identity(1,1) Not Null , captureDate smalldatetime Not Null , objectName nvarchar(128) Not Null , counterName nvarchar(128) Not Null , instanceName nvarchar(128) Not Null , value float(6) Not Null , valueType nvarchar(10) Not Null Constraint PK_dba_perfCounterMonitor Primary Key Clustered(capture_id) ); /* Create the table that controls which counters we're going to monitor */ Create Table dbo.dba_perfCounterMonitorConfig ( objectName nvarchar(128) Not Null , counterName nvarchar(128) Not Null , instanceName nvarchar(128) Null ); |
If you leave the instanceName NULL in the config table, it’ll monitor all instances. Now we’re going to insert some sample performance counters into the config table. The counters you’re interested in can, and likely will, vary.
/* Insert some perfmon counters to be monitored */ Insert Into dbo.dba_perfCounterMonitorConfig Select 'SQLServer:Buffer Manager', 'Page Life Expectancy', Null Union All Select 'SQLServer:Locks', 'Lock Requests/sec', Null Union All Select 'SQLServer:Locks', 'Lock Waits/sec', Null Union All Select 'SQLServer:Locks', 'Lock Wait Time (ms)', Null Union All Select 'SQLServer:Buffer Manager', 'Page reads/sec', Null Union All Select 'SQLServer:Buffer Manager', 'Page writes/sec', Null Union All Select 'SQLServer:Buffer Manager', 'Buffer cache hit ratio', Null Union All Select 'SQLServer:Databases', 'Transactions/sec', 'AdventureWorks' Union All Select 'SQLServer:General Statistics', 'Processes blocked', Null; |
Now let’s create our proc. This proc will run for a specified time period and will *average* the counters over that time. I personally take snapshots every 15 seconds for 4 minutes; I have a scheduled task that runs this every 5 minutes. It’s not perfect, but it gives me a good idea of what’s happening on the server.
Create Procedure dbo.dba_perfCounterMonitor_sp /* Declare Parameters */ @samplePeriod int = 240 /* how long to sample, in seconds */ , @sampleRate char(8) = '00:00:15' /* how frequently to sample, in seconds */ , @displayResults bit = 0 /* display the results when done */ As /********************************************************************************* Name: dba_perfCounterMonitor_sp Author: Michelle Ufford, http://sqlfool.com Purpose: Monitors performance counters. Uses the dba_perfCounterMonitorConfig table to manage which perf counters to monitor. @samplePeriod - specifies how long the process will try to monitor performance counters; in seconds. @sampleRate - how long inbetween samples; in seconds. The average values over sample period is then logged to the dba_perfCounterMonitor table. Notes: There are 3 basic types of performance counter calculations: Value/Base: these calculations require 2 counters. The value counter (cntr_type = 537003264) has to be divided by the base counter (cntr_type = 1073939712). Per Second: these counters are store cumulative values; the value must be compared at 2 different times to calculate the difference (cntr_type = 537003264). Point In Time: these counters show what the value of the counter is at the current point-in-time (cntr_type = 65792). No calculation is necessary to derive the value. Called by: DBA Date User Description ---------------------------------------------------------------------------- 2009-09-04 MFU Initial Release ********************************************************************************* Exec dbo.dba_perfCounterMonitor_sp @samplePeriod = 60 , @sampleRate = '00:00:01' , @displayResults = 1; *********************************************************************************/ Set NoCount On; Set XACT_Abort On; Set Ansi_Padding On; Set Ansi_Warnings On; Set ArithAbort On; Set Concat_Null_Yields_Null On; Set Numeric_RoundAbort Off; Begin /* Declare Variables */ Declare @startTime datetime , @endTime datetime , @iteration int; Select @startTime = GetDate() , @iteration = 1; Declare @samples Table ( iteration int Not Null , objectName nvarchar(128) Not Null , counterName nvarchar(128) Not Null , instanceName nvarchar(128) Not Null , cntr_value float Not Null , base_value float Null , cntr_type bigint Not Null ); Begin Try /* Start a new transaction */ Begin Transaction; /* Grab all of our counters */ Insert Into @samples Select @iteration , RTrim(dopc.object_name) , RTrim(dopc.counter_name) , RTrim(dopc.instance_name) , RTrim(dopc.cntr_value) , (Select cntr_value From sys.dm_os_performance_counters As dopc1 Where dopc1.object_name = pcml.objectName And dopc1.counter_name = pcml.counterName + ' base' And dopc1.instance_name = IsNull(pcml.instanceName, dopc.instance_name)) , dopc.cntr_type From sys.dm_os_performance_counters As dopc Join dbo.dba_perfCounterMonitorConfig As pcml On dopc.object_name = pcml.objectName And dopc.counter_name = pcml.counterName And dopc.instance_name = IsNull(pcml.instanceName, dopc.instance_name); /* During our sample period, grab our counter values and store the results */ While GetDate() < DateAdd(second, @samplePeriod, @startTime) Begin Set @iteration = @iteration + 1; Insert Into @samples Select @iteration , RTrim(dopc.object_name) , RTrim(dopc.counter_name) , RTrim(dopc.instance_name) , dopc.cntr_value , (Select cntr_value From sys.dm_os_performance_counters As dopc1 Where dopc1.object_name = pcml.objectName And dopc1.counter_name = pcml.counterName + ' base' And dopc1.instance_name = IsNull(pcml.instanceName, dopc.instance_name)) , dopc.cntr_type From sys.dm_os_performance_counters As dopc Join dbo.dba_perfCounterMonitorConfig As pcml On dopc.object_name = pcml.objectName And dopc.counter_name = pcml.counterName And dopc.instance_name = IsNull(pcml.instanceName, dopc.instance_name); /* Wait for a small delay */ WaitFor Delay @sampleRate; End; /* Grab our end time for calculations */ Set @endTime = GetDate(); /* Store the average of our point-in-time counters */ Insert Into dbo.dba_perfCounterMonitor ( captureDate , objectName , counterName , instanceName , value , valueType ) Select @startTime , objectName , counterName , instanceName , Avg(cntr_value) , 'value' From @samples Where cntr_type = 65792 Group By objectName , counterName , instanceName; /* Store the average of the value vs the base for cntr_type = 537003264 */ Insert Into dbo.dba_perfCounterMonitor ( captureDate , objectName , counterName , instanceName , value , valueType ) Select @startTime , objectName , counterName , instanceName , Avg(cntr_value)/Avg(IsNull(base_value, 1)) , 'percent' From @samples Where cntr_type = 537003264 Group By objectName , counterName , instanceName; /* Compare the first and last values for our cumulative, per-second counters */ Insert Into dbo.dba_perfCounterMonitor ( captureDate , objectName , counterName , instanceName , value , valueType ) Select @startTime , objectName , counterName , instanceName , (Max(cntr_value) - Min(cntr_value)) / DateDiff(second, @startTime, @endTime) , 'value' From @samples Where cntr_type = 272696576 Group By objectName , counterName , instanceName; /* Should we display the results of our most recent execution? */ If @displayResults = 1 Select captureDate , objectName , counterName , instanceName , value , valueType From dbo.dba_perfCounterMonitor With (NoLock) Where captureDate = Cast(@startTime As smalldatetime) Order By objectName , counterName , instanceName; /* If you have an open transaction, commit it */ If @@TranCount > 0 Commit Transaction; End Try Begin Catch /* Whoops, there was an error... rollback! */ If @@TranCount > 0 Rollback Transaction; /* Return an error message and log it */ Execute dbo.dba_logError_sp; End Catch; Set NoCount Off; Return 0; End Go |
Like I said, it’s not perfect, but it gets the job done. 
Getting an error about dba_logError_sp? Take a look at my error handling proc.
nice post Michelle, keep up the good work!!!
Awesome post. (sqlfool is always worth a read)
If you’re scratching your head for more Blog article topics, it would be great to see an example of how you consume this data and an example of decisions that are made based on the data.
Pingback: Log Buffer #162: a Carnival of the Vanities for DBAs | Pythian Group Blog
Pingback: Log Buffer #162: a Carnival of the Vanities for DBAs « PlanetMysql.ru – информация о СУБД MySQL
Well done! This is very useful
Great example of stored procedure storing in a database. Im so going to use this
and throw out an entire file based prototype out of the window.