slowness

  • Our web based product is directly accessed by many. out of which 10 customers suddenly report slowness. There sql2008 standard edition installed. upon investigation it was found that everything is fine at application and web end but all requests are taking time on given database server.

    I checked for blocking/deadlocks if any and also for long running transaction but nothing found

    Please let me know if anything else needs to be checked

    thanks

  • atulyan.aries - Monday, May 8, 2017 11:21 PM

    Our web based product is directly accessed by many. out of which 10 customers suddenly report slowness. There sql2008 standard edition installed. upon investigation it was found that everything is fine at application and web end but all requests are taking time on given database server.

    I checked for blocking/deadlocks if any and also for long running transaction but nothing found

    Please let me know if anything else needs to be checked

    thanks

    Do you maintain the instance. Are the statistics updated? You should check the indexing strategy as well.

    Igor Micev,My blog: www.igormicev.com

  • A good place to start with general troubleshooting may be looking at the database waits:
    https://www.sqlskills.com/blogs/paul/wait-statistics-or-please-tell-me-where-it-hurts/
    this can give you a general feel for what's the biggest problem in your instance, memory, CPU, I/O.

    From there, it's probably a good idea to see what are the worst performing queries in your instance:
    http://www.sqlpassion.at/archive/2015/04/20/how-to-find-your-worst-performing-sql-server-queries/

    I tend to use this query:

    SELECT TOP 25
        qs.total_elapsed_time / qs.execution_count / 1000000.0 AS average_seconds,
        qs.total_elapsed_time / 1000000.0 AS total_seconds,
        qs.total_worker_time / qs.execution_count / 1000000.0 AS avg_cpu_seconds,
        qs.total_worker_time / 1000000.0 AS total_cpu_seconds,
        qs.total_logical_reads, qs.total_logical_writes,
        qs.total_logical_reads / qs.execution_count AS average_logical_reads,
        qs.total_logical_writes / qs.execution_count AS average_logical_writes,
        qs.execution_count, qs.last_execution_time,
        o.name AS object_name, o.modify_date,
        qp.query_plan, qs.sql_handle, qs.plan_handle,
        DB_NAME(qt.dbid) AS database_name--, qt.text
      FROM sys.dm_exec_query_stats qs
        OUTER APPLY sys.dm_exec_sql_text(qs.sql_handle) as qt
        LEFT OUTER JOIN sys.objects o ON qt.objectid = o.object_id
        OUTER APPLY sys.dm_exec_query_plan(qs.plan_handle) as qp
      WHERE qt.dbid = DB_ID()
      ORDER BY qs.total_seconds DESC; --longest time to complete
      --ORDER BY qs.total_logical_reads DESC;  --most potential I/O
    --  ORDER BY qs.total_worker_time DESC;  --most CPU

  • atulyan.aries - Monday, May 8, 2017 11:21 PM

    Our web based product is directly accessed by many. out of which 10 customers suddenly report slowness. There sql2008 standard edition installed. upon investigation it was found that everything is fine at application and web end but all requests are taking time on given database server.

    I checked for blocking/deadlocks if any and also for long running transaction but nothing found

    Please let me know if anything else needs to be checked

    thanks

    Are you sure the issue is on the database side?
    Did you rule out WEB, network, AppServer issues?

    _____________
    Code for TallyGenerator

Viewing 4 posts - 1 through 3 (of 3 total)

You must be logged in to reply to this topic. Login to reply