Proposed 0.9.1 release objectives, and state of TESTFRAME

[Hal Murray]

esr at thyrsus.com said:
> I think I'll try timing a version buit to do all its DNS lookups at start.
> Network latencies have been dropping.  It is at least possible that the
> asynchronous lookup is a performance hack that we no longer need. 

I think it gets complicated, but it might be worth considering.

There are two cases: server and pool.

It would be an easy change to do the server lookups at initialization time.

The timing on the normal case isn't important.  The question is what happens on the bad case.  How long does it take a DNS lookup to time out?

But boxes using the pool probably aren't high-volume servers.  It might be OK to stall for a while.

Overall, my vote would be to not rip out threads yet.  We should collect a list of "interesting" changes like that one.

For example, when your network isn't connected yet, maybe because you are booting your laptop and it needs a wifi password.  Of course, if the network is broken, your laptop won't be able to get the time even if it knew which servers it wanted to use.

I can't put together a simple nasty case for a web server getting in trouble by using names rather than addresses.

It might be a good idea to do a DNS lookup on a non-pool server rather than using an IP Address.  The idea is for the server operator to be able to move the box behind the name by setting up a new server on a new address, switching the DNS info to point to the new address, then waiting a while.  As clients get restarted they will switch to the new system.  Eventually, is probably a long time depending on how popular the server is and such.


The pool case has to do DNS lookups after it gets started.  There are two reasons.  First, with the current setup, it probably won't get enough the first try.  After a while, the ttl expires and the caching server reloads and you get some new addresses.  After you get enough, it quits.

The second case is pool servers than stop working and/or aren't good enough.  The system will try to get some more with another DNS lookup.


-- 
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