IIS Logs / Log Parser Studio – Aggregated Hits per Server

Background

Our monitoring team has developed and rolled out scripts for monitoring our web farm.

And, we are getting alerts through email.

Quite a lot of emails are coming across and wanted to see if they are coming from same host or a combination of hosts.

 

Emails

Looked at the emails and they happen to be coming from same host.

And, so will have to engage our Network team and see how the Load Balancer is configured.

Is there a prospect that more traffic is being directed at the failing node?

Network Load Balancer

As we prepared to go to the Network Load Balancer team took the opportunity to take gather and query the IIS Logs, as well.

 

TroubleShooting

Log Parser Studio

Query


SELECT 
            To_String(date, 'yyyy-MM-dd') as dated

          , sc-status as status

          , sum (
                    case s-ip
                        when '10.0.4.25' then 1
                        else 0
                   end
               ) as S1

          , sum (
                    case s-ip
                        when '10.0.4.26' then 1
                        else 0
                   end
               ) as S2


          , sum (
                    case s-ip
                        when '10.0.4.27' then 1
                        else 0
                   end
               ) as S3

         , sum (
                    case s-ip
                        when '10.0.4.28' then 1
                        else 0
                   end
               ) as S4

          , min(TO_TIMESTAMP(date, time)) as tsRecordedMin


          , max(TO_TIMESTAMP(date, time)) as tsRecordedMax


FROM '[LOGFILEPATH]' 


where   (


           (

             TO_TIMESTAMP(date, time) 
                     between timestamp('2017/08/02 10:30:00', 'yyyy/MM/dd hh:mm:ss')  
                          and timestamp('2017/08/02 17:20:00', 'yyyy/MM/dd hh:mm:ss')
           )

       )

/*

	and  c-ip not in ('10.0.4.141')
	
*/

group by
         date
       , sc-status


order by
           dated 
         , status



Output

Time Range – 1 ( August 2nd 10:30 AM – 5:20 PM )

Results

Explanation
  1. It is difficult to make case that traffic is exhaustively being waded into a specific host

Time Range – 2 ( August 8th 5:13 PM – 8:40 PM )

Results

Explanation
  1. In our second time slot, 4700 records bearing HTTP 200 is right around average

Summary

At this time it is likely that the sufferance we are seeing with this specific host is not due to outside pressure, but internal to the host itself.

 

Internet Information (IIS) / Log Parser – Queries – String Pattern Matching

Background

Looking for File I/O Exceptions in the Event Viewer.

 

Query

Sample

Sample 001

Code


SELECT TOP 100 
 
         TimeGenerated
       , ComputerName
       , EventCategoryName
       , EventTypeName
       , EventID
       , SourceName
       , Message as Mesg
       , Strings as Strings
       , EXTRACT_TOKEN(Strings,1,'|') AS AppName
       , EXTRACT_TOKEN(Strings,2,'|') AS AppVersion
       , EXTRACT_TOKEN(Strings,3,'|') AS S3
       , EXTRACT_TOKEN(Strings,4,'|') AS Module
       , INDEX_OF(Message, 'System.IO.IOException') as indexOf
       , case INDEX_OF(Message, 'System.IO.IOException') 
            when 0 then 'N'
            when NULL then 'N'
            else 'Y'
         end as IOE
       , CASE strcnt(Message, 'System.IO.IOException')
             when 0 then 'No'
             else 'Yes'   
         end as IOException
 
from  '[LOGFILEPATH]'
 
WHERE ( EventType = 1 OR EventType = 2 )

and    INDEX_OF(Message, 'System.IO.IOException') > 0

 
ORDER BY
         TimeGenerated DESC


Output

 

Explanation

  1. INDEX_OF
    • We use INDEX_OF to find the position of the sought string in the Message column
      • When the column contains System.IO.IOException the query returns the starting position of the found pattern
      • When not found, null is returned
  2. STRCNT
    • We invoke STRCNT to count number of matches
      • When String not found, 0 return
      • When matched, number of matches

 

References

  1. StackOverflow
    • Log Parser Case Statement
      Link