NAME

nsstest - test nsswitch (and nss_ndb) functionality

SYNOPSIS

nsstest [options]action[arguments]

DESCRIPTION

This manual page documents briefly the nsstest command.

nsstest is a tool that can be used to test and measure latency in nsswitch lookups (currently only for passwd & group databases). The normal (non ndb_xx) actions tests the whole chain so can be used to test the speed of other nsswitch backends.

OPTIONS

-h: Show summary of options.
-v: Increase verbosity.
-x: Expect failure (give error if not failed)
-c: Validate returned data
-s: Keep database(s) open (setpwent, setgrent)
-C text: Compare returned data
-B bytes: Buffer size [default: 1048576 bytes]
-T seconds: Timeout limit [default: 2 s]
-N times: Repeat test [default: 0 times]
-P threads: Run in parallel [default: 0 (single-threaded)]

ACTIONS

Test the various library calls (or ndb directly for the ndb_xxx actions). The argument is typically the user/group name or uid/gids needed.

getpwnam user-name
getpwnam_r user-name
getpwuid uid
getpwuid_r uid
getpwent
getpwent_r
getgrnam group-name
getgrnam_r group-name
getgrgid gid
getgrgid_r gid
getgrent
getgrent_r
getgrouplist user-name
ndb_getpwnam_r user-name
ndb_getpwuid_r uid
ndb_getgrnam_r group-name
ndb_getgrgid_r gid

EXAMPLES

Single-Threaded username lookups in passwd database

$ nsstest getpwnam peter
Call results:
  Calls:     38561
  Time:      2.00 s
  Time/call: 51.87 µs
Test results:
  Min:       47.68 µs/c
  Avg:       51.87 µs/c
  Max:       870.70 µs/c

Multi-threaded (4 threads) parallel group lookups in group database

$ nsstest -P 4 getgrnam_r employees
Call results:
  Calls:     79659
  Time:      2.00 s
  Time/call: 25.16 µs
Test results:
  Min:       78.92 µs/c
  Avg:       100.44 µs/c
  Max:       2.03 ms/c

$ nsstest  -P10 -s -x ndb_getpwnam_r no-such-user
Call results:
  Calls:     237570
  Time:      2.01 s
  Time/call: 8.45 µs
Test results:
  Min:       34.57 µs/c
  Avg:       84.20 µs/c
  Max:       1.01 ms/c

AUTHOR

nss_ndb and tools was written by Peter Eriksson <pen@lysator.liu.se>.