From aeff5def7e11de418d55f996926cbd5818c0494d Mon Sep 17 00:00:00 2001 From: Richard Wareing Date: Wed, 6 Apr 2016 17:06:43 -0700 Subject: debug/io-stats: Adding stat for weighted & unweighted average latency Summary: - Our current approach to measuring "average fop latency" is badly flawed in that it doesn't weight the FOPs correctly according to how many occurred in the time interval. This makes Statisticians very sad. This patch adds an internally computed weighted average latency which will be far more efficient to display via ODS, as well as having the benefit of not being complete nonsense. Reviewers: kvigor, dph, sshreyas Reviewed By: sshreyas Change-Id: Ie3618f279b545610b7ed1a8482243fcc8dc53217 BUG: 1523353 Reviewed-on: https://review.gluster.org/18192 Reviewed-by: Shreyas Siravara Smoke: Gluster Build System CentOS-regression: Gluster Build System Signed-off-by: Ana M. Neri --- xlators/debug/io-stats/src/io-stats.c | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+) (limited to 'xlators') diff --git a/xlators/debug/io-stats/src/io-stats.c b/xlators/debug/io-stats/src/io-stats.c index 266f9449c9e..c0cd0e2477b 100644 --- a/xlators/debug/io-stats/src/io-stats.c +++ b/xlators/debug/io-stats/src/io-stats.c @@ -798,6 +798,11 @@ io_stats_dump_global_to_json_logfp (xlator_t *this, float fop_lat_min; float fop_lat_max; double interval_sec; + double fop_ave_usec = 0.0; + double fop_ave_usec_sum = 0.0; + double weighted_fop_ave_usec = 0.0; + double weighted_fop_ave_usec_sum = 0.0; + long total_fop_hits = 0; interval_sec = ((now->tv_sec * 1000000.0 + now->tv_usec) - (stats->started_at.tv_sec * 1000000.0 + @@ -902,7 +907,34 @@ io_stats_dump_global_to_json_logfp (xlator_t *this, ios_log (this, logfp, "\"%s.%s.fop.%s.latency_max_usec\": \"%0.2lf\",", key_prefix, str_prefix, lc_fop_name, fop_lat_max); + + fop_ave_usec_sum += fop_lat_ave; + weighted_fop_ave_usec_sum += fop_hits * fop_lat_ave; + total_fop_hits += fop_hits; + } + + if (total_fop_hits) { + weighted_fop_ave_usec = + weighted_fop_ave_usec_sum/total_fop_hits; + /* Extra key that does not print out an entry w/ 0.00 for + * intervals with no data + */ + ios_log (this, logfp, + "\"%s.%s.fop.weighted_latency_ave_usec_nozerofill\": " + "\"%0.4lf\",", + key_prefix, str_prefix, weighted_fop_ave_usec); } + ios_log (this, logfp, + "\"%s.%s.fop.weighted_latency_ave_usec\": \"%0.4lf\",", + key_prefix, str_prefix, weighted_fop_ave_usec); + ios_log (this, logfp, + "\"%s.%s.fop.weighted_fop_count\": \"%ld\",", + key_prefix, str_prefix, total_fop_hits); + + fop_ave_usec = fop_ave_usec_sum/GF_FOP_MAXVALUE; + ios_log (this, logfp, + "\"%s.%s.fop.unweighted_latency_ave_usec\":\"%0.4lf\",", + key_prefix, str_prefix, fop_ave_usec); for (i = 0; i < GF_UPCALL_FLAGS_MAXVALUE; i++) { lc_fop_name = strdupa (gf_upcall_list[i]); -- cgit