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By default all server statistics tracers are disabled as trace logging is not zero garbage and introduces cpu overhead in computing statistics. While tracing heartbeats isn't recommended in production, enabling server statistics trace output can be useful for debugging and performance tuning. To enable you will need to configure the appropriate tracers at the debug level. See the Heartbeat Trace Output Trace Loggers section for more detail.

<xvms>
  <xvmname="my-xvm">
    <heartbeats enabled="true" interval="5">
      <logging enabled="true"></logging>
      <tracing enabled="true"></tracing>
    </heartbeats>
  </xvm>
</xvms>

...

• A miss has been recorded for the pool in a given interval and it results in a new object being allocated. 
• The number of preallocated obects taken from a pool drops below the configured value for the pool depletion threshold.

Sample Trace Output

[Pool Stats]
PUT   DPUT  GET   DGET  HIT   DHIT  MISS  DMISS GROW  DGROW EVIC  DEVIC DWSH  DDWSH SIZE  PRE   CAP   NAME
38    0     16.8M 0     38    0     16.8M 0     0     0     0     0     0     0     0     0     1024  iobuf.native-32.20
1     0     62    0     1     0     61    0     0     0     0     0     0     0     0     0     1024  iobuf.native-64.21
1     0     1.0M  0     1     0     1.0M  0     0     0     0     0     0     0     0     0     1024  iobuf.native-256.23
7     0     75    0     7     0     68    0     0     0     0     0     0     0     0     0     1024  iobuf.heap-32.1

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