b4ac2c1d60
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>
58 lines
1.5 KiB
Plaintext
58 lines
1.5 KiB
Plaintext
#!/usr/bin/stap
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# usage: stap scylla_row_cache_report.stp <scylla binary>
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#
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global batch_start_time
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global batch_latencies;
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global partition_count;
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global start_time
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global latencies;
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probe process(@1).mark("row_cache_update_one_batch_start") {
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batch_start_time[tid()] = gettimeofday_ns()
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}
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probe process(@1).mark("row_cache_update_one_batch_end") {
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if (batch_start_time[tid()]) {
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lat = (gettimeofday_ns() - batch_start_time[tid()]);
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batch_latencies <<< lat;
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partition_count <<< $arg1;
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delete batch_start_time[tid()]
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}
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}
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probe process(@1).mark("row_cache_update_start") {
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start_time[tid()] = gettimeofday_us()
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}
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probe process(@1).mark("row_cache_update_end") {
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if (start_time[tid()]) {
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lat = (gettimeofday_us() - start_time[tid()]);
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latencies <<< lat;
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delete start_time[tid()]
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}
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}
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probe begin {
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printf("Measuring Scylla row cache update times ");
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}
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probe end {
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println();
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println("Total update time, (usec)");
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println(@hist_log(latencies));
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println("Time spent per partition batch (nsec)");
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print(@hist_log(batch_latencies));
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println("Partitions updated per batch:");
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println(@hist_log(partition_count));
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println("Total partitions updated:");
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println(@sum(partition_count));
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println("Average time spent per partition batch (nsec)");
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println(@avg(batch_latencies));
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println("Average time per partition per partition (nsec)");
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println(@sum(batch_latencies) / @sum(partition_count));
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}
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