Disabling hostdb sync and hostdb cache

[Vamsi Ambati <va...@neumob.com>]

When there is a burst of DNS requests, We are noticing steep memory spikes. We are using ATS 7.0 and also back ported TS-5066 and TS-5065.

If i  disable ‘proxy.config.hostdb’ , can this result in skipping  the complete hostdb module from processing  ?? My intention is to narrow down the issue and  for a while  I can sacrifice the performance without hostdb module.

traffic_ctl metric match hostdb
proxy.process.hostdb.total_lookups 0
proxy.process.hostdb.total_hits 0
proxy.process.hostdb.ttl 0.000000
proxy.process.hostdb.ttl_expires 0
proxy.process.hostdb.re_dns_on_reload 0
proxy.node.hostdb.total_lookups 0
proxy.node.hostdb.total_hits 0
proxy.node.hostdb.total_lookups_avg_10s 0
proxy.cluster.hostdb.total_lookups_avg_10s 0
proxy.node.hostdb.total_hits_avg_10s 0
proxy.cluster.hostdb.total_hits_avg_10s 0
proxy.node.hostdb.hit_ratio_avg_10s 0.000000
proxy.cluster.hostdb.hit_ratio_avg_10s 0.000000
proxy.node.hostdb.hit_ratio 0.000000
proxy.cluster.hostdb.hit_ratio 0.000000
proxy.process.hostdb.cache.current_items 104
proxy.process.hostdb.cache.current_size 34764
proxy.process.hostdb.cache.total_inserts 71697870
proxy.process.hostdb.cache.total_failed_inserts 0
proxy.process.hostdb.cache.total_lookups 143809482
proxy.process.hostdb.cache.total_hits 143809134
proxy.process.hostdb.cache.last_sync.time 0
proxy.process.hostdb.cache.last_sync.total_items 0
proxy.process.hostdb.cache.last_sync.total_size 0 


traffic_ctl config match hostdb
proxy.config.cache.hostdb.sync_frequency: 0
proxy.config.hostdb.host_file.path: XXXXXXX
proxy.config.hostdb.host_file.interval: 300
proxy.config.hostdb.ttl_mode: 3
proxy.config.hostdb.serve_stale_for: 600
proxy.config.cache.hostdb.disable_reverse_lookup: 0
proxy.config.hostdb.ip_resolve: NULL
proxy.config.hostdb: 1
proxy.config.hostdb.filename: XXXXXXXXX
proxy.config.hostdb.max_count: -1
proxy.config.hostdb.storage_path: var
proxy.config.hostdb.max_size: 10485760
proxy.config.hostdb.partitions: 64
proxy.config.hostdb.lookup_timeout: 30
proxy.config.hostdb.timeout: 1440
proxy.config.hostdb.verify_after: 720
proxy.config.hostdb.fail.timeout: 0
proxy.config.hostdb.re_dns_on_reload: 0
proxy.config.hostdb.migrate_on_demand: 0
proxy.config.hostdb.cluster: 0
proxy.config.hostdb.cluster.round_robin: 0
proxy.config.hostdb.strict_round_robin: 0
proxy.config.hostdb.timed_round_robin: 0



Vamsi

Re: Disabling hostdb sync and hostdb cache

[Reindl Harald <h....@thelounge.net>]

Am 21.12.2016 um 21:51 schrieb Vamsi Ambati:
> When there is a burst of DNS requests, We are noticing steep memory
> spikes. We are using ATS 7.0 and also back ported TS-5066 and TS-5065.
>
> If i  disable \u2018proxy.config.hostdb\u2019 , can this result in skipping  the
> complete hostdb module from processing

dunno - but this database and code should not exist at all - imagine a 
world where every piece of serversoftware brings it's own 
host-cache-database instead just use the configured resolver and let 
caching be it's job

in-memory caching of hot dns requests is fine to not have a dns query at 
every incoming http request - but a persistent on-disk database is 
questionable to say it nice