Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.

TCPIP Networks for DBAs

5,170 views

Published on

Everything DBAs should know about TCPIP networks - captures, firewalls, roundtrips, latency and bandwidth.

Published in: Technology, Business
  • Be the first to comment

TCPIP Networks for DBAs

  1. 1. Everything a DBA Should Know about TCP/IP Networks<br />Chen (Gwen) Shapirahttp://prodlife.wordpress.com<br />
  2. 2. My Stories<br />ORA-12545 on connection to RAC<br />Job does not finish running<br />Reading 2M rows<br />Copying redo logs to DR site<br />
  3. 3. Will Show<br />Collect hard data – Don’t guess<br />When & What to tune<br />Back of the envelope calculations<br />
  4. 4. ORA-12545 Connecting to RAC <br />
  5. 5. Why guess when you canCapture?<br />
  6. 6.
  7. 7.
  8. 8.
  9. 9. I want to connect<br />Go to that server! Bye!<br />Go where???<br />
  10. 10. Solutions<br />Fix LOCAL_LISTENER<br />Fix DNS<br />
  11. 11. Batch Job Never Finishes<br />
  12. 12. Capture on bothClient & Server<br />
  13. 13.
  14. 14.
  15. 15. Run this procedure<br />ACK!<br />
  16. 16. Two hours later…<br />Hello? Are you alive? No?<br />BYE!<br />Waiting<br />
  17. 17. The firewall is eating my packets!<br />
  18. 18. Solutions<br />Talk to network admin<br />Configure SQLNET.EXPIRE_TIME<br />Configure tcp_keepalive_time<br />
  19. 19. Give Me 2M Rows ASAP<br />
  20. 20. Start with Wait Events<br />
  21. 21. SQL*Net Message to client-Meaningless<br />
  22. 22. SQL*Net Message from client-Nearly Meaningless<br />
  23. 23. Do the numbers make sense?<br />Bytes Sent<br />Time<br />Roundtrips<br />
  24. 24. Tune the ArraySize<br />Or setFetchSize()<br />With 2M rows:<br /><ul><li>Fetch 10 => 200,000 Roundtrips
  25. 25. Fetch 5000 => 400 Roundtrips</li></li></ul><li>(Don’t) Tune SDU<br />Oracle’s buffer – 2K or 8K <br />Can set to max – 32K<br />Can set to multiple of 1476 byte<br />Highly unlikely target<br />
  26. 26. Beware:Compulsive Tuning Disorder<br />
  27. 27. Get Redo Logs to DR Site<br />
  28. 28. Q1: Bandwidth?<br />
  29. 29. OC3 =&gt; 155 Mb/s =&gt; ~ 70G/hour =&gt; ~ 60G with headers<br />
  30. 30. Key problem:Line utilization<br />
  31. 31. Q2: Latency?<br />TNSPing Roundtrip time – 500ms<br />
  32. 32. Data &lt; 1500 bytes<br />500 ms<br />ACK<br />
  33. 33. Data &lt; 1500 bytes<br />ACK<br />
  34. 34. 155Mb/s * 500ms=9.6MBytes<br />
  35. 35. Advertised Windows<br />net.core.wmem_default<br />net.core.wmem_max<br />net.core.rmem_default<br />net.core.rmem_max<br />
  36. 36. Congestion Window<br />Errors<br />Window Size<br />Time<br />
  37. 37. WAN Accelarator<br />$<br />$<br />$<br />$<br />
  38. 38. Rememeber<br />Collect hard data – Don’t guess<br />When & What to tune<br />Back of the envelope calculations<br />
  39. 39. Questions?<br />

×