3 Commits

Author SHA1 Message Date
Tomasz Grabiec
6ba272a610 debug: scylla_row_cache_report: Remove duplicated phrase from printout
Message-Id: <1520412164-10746-1-git-send-email-tgrabiec@scylladb.com>
2018-03-07 11:15:57 +02:00
Tomasz Grabiec
95b3eaac97 debug: Allow running scylla_row_cache_report.stp script against a running process
Message-Id: <1504776359-16424-1-git-send-email-tgrabiec@scylladb.com>
2017-09-11 14:17:30 +03:00
Glauber Costa
b4ac2c1d60 debug: add systemtap script to measure interesting latencies during cache updates.
Example output:

Measuring Scylla row cache update times ^C
Total update time, (usec)
value |-------------------------------------------------- count
    2 |                                                   0
    4 |                                                   0
    8 |@@                                                 2
   16 |@@@                                                3
   32 |                                                   0
   64 |                                                   0
  128 |@@@@                                               4
  256 |@@                                                 2
  512 |                                                   0
 1024 |                                                   0

Time spent per partition batch (nsec)
 value |-------------------------------------------------- count
   128 |                                                       0
   256 |                                                       0
   512 |                                                      43
  1024 |                                                       2
  2048 |                                                       2
  4096 |                                                      45
  8192 |                                                     349
 16384 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@  61494
 32768 |@@@@@@@@@@@@@@@@@                                  21497
 65536 |                                                       0
131072 |                                                       0

Partitions updated per batch:
value |-------------------------------------------------- count
    0 |                                                      57
    1 |                                                      46
    2 |                                                      76
    4 |                                                     134
    8 |                                                     324
   16 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@  82795
   32 |                                                       0
   64 |                                                       0

Total partitions updated: 2485000
Average time spent per partition batch (nsec): 28816
Average time per partition per partition (nsec): 967

Signed-off-by: Glauber Costa <glauber@scylladb.com>
2017-01-26 22:15:16 -05:00