19,973 reputation
11943
bio website ripple.com
location Northern California
age 44
visits member for 2 years, 8 months
seen 1 hour ago

I am Chief Cryptographer at Ripple Labs (formerly OpenCoin) and one of the architects of the Ripple payment system.


Jan
27
comment Cisco Switch went mad
Disconnect all ports except the port you have your management machine connected to. It's possible that it's something silly, like portfast enabled or spanning tree disabled on a port that leads back to another port on the same switch indirectly.
Jan
24
comment Confusion about rDNS
Yes, that will be a problem. If the machine's name is blah.foo1.bar, then the CNAMEs should point to blah.foo1.bar, not foo1.bar.
Jan
24
comment Mysql ram usage
What precisely do you mean by "ram usage on this server"? Do you mean the actual amount of physical RAM used?
Jan
23
comment Determining cause of SSD failure after 30-ish minutes
I suspect heat. The drive should be able to report its internal temperature via SMART.
Jan
23
comment “Connection” HTTP header in load balancers
It depends whether the load balancer is or is not a hop at the HTTP level. Routers aren't hops, right? But proxies are. If the load balancer acts like a router, it's not a hop. If it acts more like a proxy, it is. Many types of load balancers exist.
Jan
22
comment Improve system performance with all my extra RAM?
@user206442 Linux will already do that, except it will do it if and only if it's the best use of that RAM.
Jan
22
comment SSH port tunnel disconnects with “select: Invalid argument”
You can raise FD_SETSIZE. It just takes a few tiny header changes. Ideally, any code that still uses select would be changed not to.
Jan
21
comment fastcgi php and memory limit
@GiovanniNervi How is that a problem? Are processes getting killed? Do you need the memory for something else?
Jan
21
comment Wireless client bridge not working on network- any potentially workable alternatives?
If a simple wireless bridge would allow you to add more clients to a network wirelessly, we wouldn't need WDS.
Jan
21
comment fastcgi php and memory limit
@GiovanniNervi It sounds like you didn't ask the question you actually wanted to ask. If you're having some kind of problem, you should describe it in as much detail as possible. (Much of the physical memory you're seeing the processes use is likely shared.)
Jan
21
comment fastcgi php and memory limit
@GiovanniNervi It's not a virtual memory limit for the process, just for one way the PHP system allocates virtual memory. (See updates.)
Jan
21
comment Why server writes much more than reading the disk
What does "CPU was low" mean? Were one or more cores maxed? Also, the chart doesn't ever get anywhere near 100%.
Jan
21
comment Why is file rewrite slower?
Rewrite requires dealing with the old contents, write does not. What are your journalling settings?
Jan
21
comment Reverse DNS does not contain the hostname
Why would you check anything else? Are you concerned about other possible problems? Why not fix this one first?
Jan
21
comment Why server writes much more than reading the disk
@vutran What problem? Nothing in your post suggests a problem except your claim that your application is unacceptably slow. You should try to figure out why. Do you have some reason to suspect that I/O is the issue? Were any cores maxed?
Jan
21
comment Why server writes much more than reading the disk
When it's slow, is the CPU maxed? Are one or more cores maxed?
Jan
17
comment Memory usage reported incorrectly on OpenVZ VPS
@JustinMrkva What makes you think one has anything to do with the other? And what seems incorrect about that memory report? (Your only choices with memory are to use it or to waste it. You can't save it for later. Are you concerned that very little memory is being wasted?)
Jan
17
comment Memory usage reported incorrectly on OpenVZ VPS
What does "it fails" means? What fails? How does it fail? Does it display an error message? What makes you think the problem has anything to do with memory?
Jan
6
comment Collision errors reported by Cisco router interface
Simple rule of thumb: Unless you have a very good reason to do otherwise, do not ever force the speed or duplex on an Ethernet device unless you are certain that the device on the other end has the speed and duplex both forced to precisely the same settings you are forcing your end to. And never, ever force the speed or duplex on Gigabit devices if the connection is copper.
Jan
6
comment Fetching CPU usage and memory leak from the server
You didn't put JmeterPlug.jar in the bin folder.