21,228 reputation
12347
bio website ripple.com
location Oakland, CA
age 44
visits member for 3 years
seen yesterday

I am Chief Cryptographer at Ripple Labs and one of the architects of the Ripple payment system.


Apr
24
answered High iowait despite small amount of write/read
Apr
24
comment Which settings schould be changed to lower apache CPU usage and use more RAM?
It's good that you recognize that it's important that RAM be used. I'd start out by undoing any tuning or tweaking that's already been done. You would be surprised by how often someone has tuned the machine to keep as much RAM free as possible -- the opposite of what you would want to do to improve performance. Look carefully at any "tweaks" to the OS's vm settings.
Apr
21
comment How to block CloudFront or other CDN to access my website
It's not clear what it is precisely you are trying to prevent. Can you clarify precisely what problem you are trying to solve?
Apr
19
awarded  Enlightened
Apr
19
awarded  Nice Answer
Apr
18
revised Switch the SSL provider after Heartbleed bug instead of revoking
added 132 characters in body
Apr
18
answered Switch the SSL provider after Heartbleed bug instead of revoking
Apr
17
comment Why is chroot system call not available to non root user?
The limitations section of the article on chroot goes into more detail, as the excerpt says.
Apr
17
answered Why is chroot system call not available to non root user?
Apr
17
comment Apache 2.4.9 100% CPU load of random workers
And then every single byte that was swapped out got swapped back in? That's totally implausible. To say it's "most likely" is completely unjustified.
Apr
17
comment Apache 2.4.9 100% CPU load of random workers
This seems unlikely given the amount of free physical memory he has and the fact that none of his swap is used.
Apr
17
comment Apache 2.4.9 100% CPU load of random workers
That strace shows a send call for zero bytes, which makes no sense. It makes even less sense after a read hit. Something seems very wrong with the logic of whatever process you were tracing.
Apr
16
comment How to access device on switch from another computer?
I don't see where you describe any problem. You say you tried setting both NICs to different static IP addresses. Presumably that didn't work or you wouldn't be asking the question, right? So what went wrong? What is the actual problem? Are these two different networks or are these two switches in turn switches to each other?
Apr
15
comment What does this notice mean “SNI: extension not received from the client”, in stunnel log
Are you sure this syntax is correct: sni = websockets:mailxf.test.int?
Apr
14
comment Reading tracert output - what does this address mean?
Most likely, lax20 is the router's identifier, xe is the interface type, and 9-3-0 means something like slot 9, module 3, port 0.
Apr
14
comment Why can nginx access /etc/passwd?
If you have sensitive information in any of those files, then you've done something wrong.
Apr
6
comment What could increase the consumed server memory amount when just upgrade the RAM?
Wouldn't you be upset if you added more RAM to improve server performance and instead the server just left that RAM empty, wasting it?
Apr
6
comment can Iowait cause significant RAM consumption increase
It could be either way. It's also possible that for some reason I/O performance drops, causing data to back up in RAM.
Apr
6
comment Patch-panel for phone splitter
Series?! You have to wire phone jacks in parallel.
Apr
5
comment How to handle an abuse complaint?
What makes them think this is abuse rather than normal traffic? Is the volume excessive? Do you operate any nameservers? If so, are they recursive? (If you don't have a procedure for handling abuse complaints, you probably shouldn't be running a server that's open to the Internet.)