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Memory and Priority Jul 20, 2011 | Rei
Still keeping an eye on the Stat Server's memory usage. Also noticed it was running at "nice 10" which has been fixed thanks to "renice 1 -p 60227".

33914 rei 1 54 10 9340K 2892K select 0 5:42 0.00% screen
60227 rei 1 45 1 10920K 7500K accept 3 5:30 0.00% ss

Memory usage didn't immediately go up after freeing 4500 records.

We're using GLib C's malloc() and free() memory management features. Every call to free places the reallocated block on a free list. So if I deleted everything, there's always a chance sbrk() could be called to reduce the heap size. But given the nature of this program... that seems unlikely. The newest records are at the end, and the ones freed with be scattered all over the place, most densely packed at the beginning. Of course, after a free, the memory will be reused before the next sbrk() is made ... anyways, so long as we never go near 100M, I think I'll feel confident there are no memory leaks. But if it goes above 30M or 50M without much change in records, I'll have to consider using a MemLeak detector.

Also this time Bing was doing a DoS. lol What's with them requesting 30 pages in 2 seconds? Could be a spoofed User Agent. Meh... no harm done.
Stats Server DoS Issues Jul 18, 2011 | Rei
As expected, my code wasn't perfect. We had a few DoS attacks ( defined as more than 20 page requests in 2 seconds from 1 individual ) which caused an unexplained termination of the stats server.

First time it happened, it took the whole site down with it. I recoded a few things so that if the stats server died, the site continues to run without it.

Simplified several parts of code, traced the program execution, and recreated the scenario. At first I didn't realize why it was exiting at a dprintf() point.

Uploaded patch ss-0.3 which ran until the next DoS attack. Crashed again, but this time the site stayed up.

Looked over the code again... and noticed dprintf() was being called twice, but was requested only once. Added a return value to the function that might call dprintf to report if it did so I don't call it the second time.

Hopefully this is the last time I have to deal with it....

Still worried about the simplified while loops tho. They have a possibility of going infinite. I'll know by tomorrow if the code is solid.
PM Notifications by email Jul 17, 2011 | Rei
Long overdue, but finally you will receive an email notification ( generally within 5 minutes ) when a new PM is sent to you.

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