22,188 reputation
12450
bio website ripplelabs.com
location Oakland, California
age 45
visits member for 3 years, 5 months
seen 10 hours ago

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


Jan
21
comment Apache 2.4 prefork, MySQL 5.6 and 2GB RAM
Your top output shows 1.4GB of RAM (68%) inactive, which means it's available for use for any purpose. Why do you think there's a problem?
Jan
16
revised Server virtual processors and processing units
deleted 1 character in body
Jan
15
answered Server virtual processors and processing units
Jan
13
comment kworker consuming +90% IO and zero disk write
You may want to use perf to find out what kworker is doing as a troubleshooting step.
Jan
13
comment Where is my RAM going?
Use slabtop to see if it's the dentry cache.
Jan
12
comment High process count and load
The first question is -- what are those 1,877 processes?
Jan
7
comment Linux is sending ARP requests to hosts in other subnets?
Something is probably wrong in the netmasks or routing table on host A.
Jan
6
comment Where did my RAM go?
@mirabilos I explained the issue and gave a link to an example of something that could cause it. The example was extra, not needed to understand the answer. (It just happened, by sheer luck, to be exactly the same cause as his.) Other people who have the same issue as him likely won't have the same cause, so it doesn't really improve the answer to go into more detail. But feel free to propose an edit.
Jan
6
answered Why wouldn't I want to enable swap?
Jan
6
comment svchost.exe -k regsvc using over 1.2 GB RAM
How did you determine that it was using over 1.2 GB of RAM? (Please be as specific as possible. What tool did you use? What exactly did it report?)
Jan
5
awarded  Nice Answer
Jan
5
comment Where did my RAM go?
@Benjamin I don't know any way to see what's in the dentry cache. But running strace may be instructive. Do you use libcurl? What's your app doing?
Jan
5
comment Where did my RAM go?
@Benjamin Follow my link for one example of how this can happen. Also, look at what the web application is actually doing.
Jan
5
answered Where did my RAM go?
Jan
2
answered What happen if a systemd service reach its MemoryLimit?
Jan
2
comment Clearing Memory (RAM) Cache on CentOS
Are you seriously asking how to get your computer to waste more memory rather than using it efficiently?
Jan
2
comment How many bits of entropy per byte read from /dev/random and /dev/urandom?
@DanielKauffman I have no idea what that means.
Jan
2
comment How many bits of entropy per byte read from /dev/random and /dev/urandom?
@DanielKauffman You can already read however many bytes you want/need from /dev/urandom directly. Hashing is really only helpful if you want to combine entropy from multiple sources.
Dec
31
answered How many bits of entropy per byte read from /dev/random and /dev/urandom?
Dec
30
comment Data Transfer Speed Hardware Config
@Alan When it maxed out, what maxed out? CPU? Memory? I/O?