stap-exporter(8)

1STAPBPF(8)                  System Manager's Manual                 STAPBPF(8)
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NAME

6       stap-exporter - systemtap-prometheus interoperation mechanism
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SYNOPSIS

12       stap-exporter [ OPTIONS ]
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DESCRIPTION

16       stap-exporter  is  a  small  program that manages systemtap session and
17       relays prometheus metrics from the sessions  to  remote  requesters  on
18       demand.  stap-exporter  runs as a systemd service and listens to a con‐
19       figurable TCP port for requests. stap-exporter is  capable  of  running
20       multiple  stap scripts at a time. Metrics for a given script are avail‐
21       able at the URL [HOSTNAME]:[PORT]/[SCRIPTNAME]. PORT defaults  to  9900
22       but  is  configurable, see OPTIONS below. After installation, the stap-
23       exporter systemd service should be manually enabled.
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26       If stap-exporter receives a request for metrics from a script  that  is
27       already  running, the script's prometheus probes will trigger. The met‐
28       rics  sent  back   to   the   requester   are   specified   using   the
29       prometheus_dump_arrayN  family of macros (see EXAMPLE below).  If stap-
30       exporter receives a request for a script that is not currently running,
31       stap-exporter  will  search  systemtap.examples for scripts with script
32       name given in the URL.  If found, stap-exporter will begin running this
33       script.  At  launch,  stap-exporter  will automatically run all scripts
34       found in systemtap.examples/stap-exporter-scripts.
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OPTIONS

39       The stap-exporter program supports the  following  options.  Any  other
40       option prints a list of supported options.
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42       -p --port
43              Listen to the specified TCP port for requests. Port 9900 is used
44              by default.
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46       -t --timeout
47              Scripts that run longer than TIMEOUT seconds will  be  automati‐
48              cally  shutdown.  Each time stap-exporter recieves a request for
49              a particular script, it  resets  that  script's  remaining  time
50              until shutdown. By default, scripts will run until stap-exporter
51              is terminated.
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53       -h --help
54              Print help message.
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EXAMPLES

58       Suppose that example.stp contains the following stap script:
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61              global arr
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63              probe syscall.read {
64                  arr[tid(), cpu()]++
65              }
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67              probe prometheus {
68                  @prometheus_dump_array2(arr, "count", "tid", "cpu")
69              }
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72       The prometheus_dump_arrayN macros are used to produce metrics  from  an
73       array.   Systemtap  provides  a  prometheus_dump_arrayN macro for all N
74       from 1 to 8.  The first argument of the macros represents an array with
75       N-element keys.  The second argument represents the name of the metric.
76       The remaining N arguments represent the names of the metric's labels.
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79              $ stap-exporter -p 9999 -t 60
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81              $ curl localhost:9999/example.stp
82              Refresh page to access metrics.
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84              $ curl localhost:9999/example.stp
85              count{tid="12614",cpu="0"} 9
86              count{tid="12170",cpu="3"} 107
87              count{tid="1802",cpu="0"} 33687
88              count{tid="12617",cpu="1"} 99
89              [...]
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SAFETY AND SECURITY

94       See the stap(1) manual page for additional information  on  safety  and
95       security.
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BUGS

103       Use  the  Bugzilla  link  of  the project web page or our mailing list.
104       http://sourceware.org/systemtap/, <systemtap@sourceware.org>.
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108                                                                    STAPBPF(8)