So far i am very glad to have started the upgrade. There are many changes in the code.
The most important now - they redid locking. However it's kind a diffrent from i did, but, perhaps more right.
Instead of splitting queues to pieces, i saw that now there are different locks for read and write. That sounds to be promising as now it will be possible to use reading in parallel. Perhaps its good, but testing didn't show any performance increase yet.
And i don't remember this before:
It's from DCconfig_poller_get_items - function to retrieve items from queues to check. I think it's just not right.
It's much better to make async requesting in every type of check. Do some reasonable timeouts and just _forget_ about priorities, different timing and unreachable pollers.
I tried it for snmp and saw no negative impact.
Whatever number hosts are not reachable the thread will wait only one timeout of 2 seconds either for one or eight thousand hosts.
Some disadvantage of async pollers is that in theory they will work a bit longer for pack batch of hosts then they would do for a single item. Each pack of items might be processed from 2 to 8 seconds, so it's not good for polling data more frequent then 10 seconds.
But according to my tests end expereince, its not worse then existing system, under comparable NVPS it will be very fast, but don't expect 1-2 second polling delays from the system processing 20-30kNVPS
The most important now - they redid locking. However it's kind a diffrent from i did, but, perhaps more right.
Instead of splitting queues to pieces, i saw that now there are different locks for read and write. That sounds to be promising as now it will be possible to use reading in parallel. Perhaps its good, but testing didn't show any performance increase yet.
And i don't remember this before:
It's much better to make async requesting in every type of check. Do some reasonable timeouts and just _forget_ about priorities, different timing and unreachable pollers.
I tried it for snmp and saw no negative impact.
Whatever number hosts are not reachable the thread will wait only one timeout of 2 seconds either for one or eight thousand hosts.
Some disadvantage of async pollers is that in theory they will work a bit longer for pack batch of hosts then they would do for a single item. Each pack of items might be processed from 2 to 8 seconds, so it's not good for polling data more frequent then 10 seconds.
But according to my tests end expereince, its not worse then existing system, under comparable NVPS it will be very fast, but don't expect 1-2 second polling delays from the system processing 20-30kNVPS
No comments:
Post a Comment