[Samba] samba 4.7.3 DLZ performance regression

[Arthur Ramsey]

Thanks Andrew, much better than vanilla 4.7.3 but it is still performs 
much worse than vanilla 4.7.0 especially for DLZ zones.

$ dig @127.0.0.1 google.com
$ perl -e "foreach(1..500) { system('dig', '@127.0.0.1', 'google.com'); }" | grep time > 4.7.0_external.log
$ perl -e "foreach(1..500) { system('dig', '@127.0.0.1', 'mediture.dom'); }" | grep time > 4.7.0_internal.log

$ cat 4.7.0_internal.log.gz | perl dns_stats.pl
Max process time (ms): 7
Standard deviation of process time (ms): 0.456807778713746
Mean process time (ms): 2.088

$ cat 4.7.0_external.log.gz | perl dns_stats.pl
Max process time (ms): 3
Standard deviation of process time (ms): 0.332814559570528
Mean process time (ms): 1.884

Then after installing Samba4, restarting samba4 and restarting BIND:

$ dig @127.0.0.1 google.com
$ perl -e "foreach(1..500) { system('dig', '@127.0.0.1', 'google.com'); }" | grep time > 4.7.3_external.log
$ perl -e "foreach(1..500) { system('dig', '@127.0.0.1', 'mediture.dom'); }" | grep time > 4.7.3_internal.log

$ cat 4.7.3_external.log.gz | perl dns_stats.pl
Max process time (ms): 985
Standard deviation of process time (ms): 169.45778909383
Mean process time (ms): 66.36

$ cat 4.7.3_internal.log.gz | perl dns_stats.pl
Max process time (ms): 975
Standard deviation of process time (ms): 238.891289268035
Mean process time (ms): 404.935871743487

On 12/14/2017 05:44 PM, Andrew Bartlett wrote:
>   Attached is a possible set of patches.
>
> As indicated, a search for a not-existing name, be it one that will
> match with a wildcard or one that wont, will still be slow.
>
> Andrew Bartlett
>


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