sar Results Explained

Howdy!

I won’t be going into a whole lot of detail about sar as this has been documented elsewhere multiple times but basically, SAR stands for System Activity Report and as its name suggests, the sar command is used to collect,report & save CPU, Memory, I/O usage in Unix like operating systems. The SAR command produces reports on the fly and can also save the reports in the log files as well. The sar man page states:

The sar command writes to standard output the contents of selected cumulative activity counters in the operating system. The accounting system, based on the values in the count and interval parameters, writes information the specified number of times spaced at the specified intervals in seconds. If the interval parameter is set to zero, the sar command displays the average statistics for the time since the system was started. If the interval parameter is specified without the count parameter, then reports
are generated continuously.

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What is the Apache Scoreboard?

As a request comes in, it is denoted in the scoreboard. The scoreboard itself is basically a way to keep track of each incoming, waiting, and completing connections. These connections are broken down into the following types:

  1. “_” Waiting for Connection
  2. “S” Starting up
  3. “R” Reading Request
  4. “W” Sending Reply
  5. “K” Keepalive (read)
  6. “D” DNS Lookup
  7. “C” Closing connection
  8. “L” Logging
  9. “G” Gracefully finishing
  10. “I” Idle cleanup of worker
  11. “.” Open slot with no current process

Here is an example of the apache scoreboard in WHM:
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