Displaying the request histogram facility statistics values
The rhist s request returns the current values for all latency ranges which have a nonzero count.
Table 1 describes the keywords for the rhist s response, in the order that they appear in the output. These keywords are used only when the mmpmon command is invoked with the -p flag.
| Keyword | Description |
|---|---|
| _n_ | IP address of the node responding. This is the address by which GPFS knows the node. |
| _nn_ | The hostname that corresponds to the IP address (the _n_ value). |
| _req_ | The action requested. In this case, the value is s. |
| _rc_ | Indicates the status of the operation. |
| _t_ | Indicates the current time of day in seconds (absolute seconds since Epoch (1970)). |
| _tu_ | Microseconds part of the current time of day. |
| _k_ | The kind, r or w, (read or write) depending on what the statistics are for. |
| _R_ | Request size range, minimum and maximum number of bytes. |
| _NR_ | Number of requests that fell in this size range. |
| _L_ | Latency range, minimum and maximum, in milliseconds. |
| _NL_ | Number of requests that fell in this latency range. The sum of all _NL_ values for a request size range equals the _NR_ value for that size range. |
If the facility has been previously enabled, the rhist s request still displays the statistics even if rhist off is currently in effect. This allows turning the histogram statistics on and off between known points and reading them later. If there are no mounted file systems at the time rhist s is issued, then the statistics are still displayed.
An _rc_ value of 16 indicates that the histogram operations lock is busy. Retry the request.