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Sep
26
comment Apache2.4/nginx - route all traffic to requesting host?
Yeah if you can rely on %{REMOTE_ADDR} being a real machine's address that works very well. (Alternatively if you can always assume localhost will serve what you need that's an option too - just slap that in there.)
Sep
26
comment Apache2.4/nginx - route all traffic to requesting host?
@StefanKendall It's slightly less horrible in that case - the most egregious risk (cross-site scripting) is much more limited. I would however recommend against the xp.io style solution (because theoretically an external IP can be plugged into it and would then open up the potential for XSS again). Restricting access to the redirecting URLs (by password or ACL) would also be wise.
Sep
26
answered Apache2.4/nginx - route all traffic to requesting host?
Sep
19
comment what percentage of iowait is considered to be high?
@GabrielSousa I've seen it on a variety of systems ranging from 1-CPU 486s to 8-core Sun machines. On modern multicore systems with the same kinds of workloads you could probably sustain even higher load averages as long as the OS scheduler and the disk/memory subsystems can deal with it. Load average (like iowait, %CPU busy, etc.) is not always directly correlated to performance. It is one component in a system which ultimately determines performance.
Sep
17
awarded  Great Answer
Sep
16
comment what percentage of iowait is considered to be high?
@kofemann Load Average (RunQueue depth) is a useful metric, but it too can be misleading. I've had systems operating with load averages of 10-20 but the users had no issues with performance (lots of processes waiting, but they only need a couple of microseconds and then they give the CPU back). User-perceived performance is always the great and final arbiter.
Sep
16
comment what percentage of iowait is considered to be high?
(For what it's worth I subscribe to the user-centered view of performance tuning: A computer can be horribly overloaded by the numbers, but working beautifully from a user perspective, and users are the ones who open support tickets and complain about things, so it's their opinion that matters.)
Sep
16
answered what percentage of iowait is considered to be high?
Sep
16
comment To get PHP communicate with PostgreSQL
FYI: This is being downvoted for two reasons: (a) it's commented out as written, so it has no effect, and (b) If you uncomment it it's dangerous: You are allowing ANYONE on the local system to connect to any Postgres database as any user (including the DB superuser) - you're one badly written PHP script away from someone using SQL injection to drop your production databases.
Sep
9
comment Setting timezone to UTC in unattended install
I'm not sure about the virtualized guests (bhyve or such?) - I would reboot after doing this just to be 100% sure you catch everything though. (Same logic as fixing timezones for DST changes: you could restart every daemon on the box & hope you don't miss anything, or you could just reboot, let ntpdate re-sync the clock on boot, and then know everything is using the correct time zone.)
Sep
8
comment Why is hash join slow in postgresql 9.1?
@Dmitro You could try running a manual VACUUM ANALYZE on the table to update the query planner's statistics, but like Tometzky said if the underlying query is confusing the planner this may not help (and if it does the "help" may not be persistent: the next time the planner statistics refresh it could change its mind again). Rewriting the query to make it easier for the planner to understand is The Right Fix (same as for any database system).
Sep
8
answered Setting timezone to UTC in unattended install
Sep
8
comment localhost in a DNS zone
5 years on but worth clarifying: 4.1 of RFC 1912 is explicit that the localhost zone should exist on the server (so if it gets a request just plain "localhost" it doesn't pass it up the chain to the next server), that's a far cry from including localhost in say example.com's zone (creating localhost.example.com), which it is equally explicit in saying you should not do because of possible unintended side effects. The expectation is for "localhost" to be a special, magical, fully-qualified domain in its own right.
Sep
8
comment localhost in a DNS zone
5 years on but worth clarifying: 4.1 of RFC 1912 is explicit that the localhost zone should exist on the server (so if it gets a request just plain "localhost" it doesn't pass it up the chain to the next server), that's a far cry from including localhost in say example.com's zone (creating localhost.example.com), which it is equally explicit in saying you should not do because of possible unintended side effects. The expectation is for "localhost" to be a special, magical, fully-qualified domain in its own right.
Aug
31
awarded  Caucus
Aug
17
awarded  Nice Answer
Aug
11
comment Why are cronjobs running at the wrong time?
@WildVelociraptor Yeah syslog will also use the old timezone data until restarted (so it's going to timestamp things wrong even though they're running at the right time). Anything else that's long-running and started before the timezone data changed will exhibit similar behavior, which is why a reboot is generally indicated.
Jul
13
comment How can I see Time-To-Live (TTL) for a DNS record?
@Jasen Yes, that's definitely possible (It indicates something important as well: The DNS admin will be buying drinks at the next company outing for screwing up the migration!)
Jul
7
comment Sendmail sends unsolicited emails
That would be my guess as well. Find and fix the offending web application and your spam problems will disappear.
Jul
7
revised Postgres on OS X can't find postgis extension control file
edited title