Back when google first released their 8.8.8.8 and 8.8.4.4 dns servers I did some profiling, and they are way faster for our location. A more recent test confirms this is still the case. However, after careful consideration I declined to make the switch away from our ISP DNS, because looking at a few snapshots of our traffic, so many of our requests were for cdn addresses. Using a central DNS for lookups to CDN sites [...]

I’ve tried about 1000x things, but I can’t seem to figure out why a simple django website is slow using apache 2.2.14/wsgi latest / django 1.3. I’ve confirmed the problem isn’t our database by turning on mysql slow query logging. I’ve reviewed the wsgi daemon configuration settings about another 100x times but still don’t understand why runserver is currently faster than apache! Here is my apache config, let me know if there are other items [...]

I am making a drive image that will be deployed to several computers, and I’m tweaking it for performance. It is a Windows XP image. Considering there is only one hard drive, will the machine gain performance if I place the Windows pagefile on a separate partition, possibly FAT16 (instead of NTFS as the OS partition)? I’m thinking of this because Linux does it, actually it uses the raw partition as “swap space”, which is [...]

Are there ApacheTop like tool for Nginx for measuring hit contents? I want to find out the most popular URL from the web server log (Nginx) Asked by Howard Although Nginx Stub module might come in handy but i find it less informative than apache counterpart. For your requirement, wtop might be the best. Answered by kaji Check more discussion of this question. Bookmark on Delicious Digg this post Recommend on Facebook share via Reddit [...]

I’ve and Oracle (11 Enterprise) schema with a table CREATE TABLE USER.WSP_BUNDLE ( NODE_ID RAW(16) NOT NULL, BUNDLE_DATA BLOB NOT NULL ); CREATE UNIQUE INDEX USER.WSP_BUNDLE_IDX ON USER.WSP_BUNDLE(NODE_ID); and 3′rd party library (Java 6, JDBC – latest jdbc driver) that manipulate it. Oracle profiler (tkprof) shows that about 50% of overall time the lib execute such statement: update WSP_BUNDLE set BUNDLE_DATA = :1 where NODE_ID = :2 TKProf data Plan Hash: 4085453680 update WSP_BUNDLE set [...]

According to this paper on Facebook’s Haystack: “Because of how the NAS appliances manage directory metadata, placing thousands of files in a directory was extremely inefficient as the directory’s blockmap was too large to be cached effectively by the appliance. Consequently it was common to incur more than 10 disk operations to retrieve a single image. After reducing directory sizes to hundreds of images per directory, the resulting system would still generally incur 3 disk [...]

Background: I use a cluster with my coworkers and if anyone writes too many big files at the same time I can’t even move the cursor in vim (the horror!). I’m not sure if it is more related to the number of files open or the “bandwith” of hard drive being used but it definitely only happens when a big write operation is taking place (including downloading big files). I know you can limit hard [...]

With a fresh install of nginx, I obtain these results running apache benchmark, which I feel are very very odd. The page fetched is the default static index.html test page installed by nginx. Running ab locally has very high requests/per second, but remotely it’s drastically lower. I have disabled my firewall temporarily withese tests. AB -n 100 running locally: Document Path: / Document Length: 3698 bytesConcurrency Level: 1 Time taken for tests: 0.21347 seconds Complete [...]

How many logs/second can usually be handled by syslog servers? By syslog servers, I am referring to rsyslog, syslog-ng, splunk etc. The intent of the question is to find out at what logs/second rate the OS (Linux kernel >=3.0) becomes bottle-neck. So far, I am able to forward about 10,000 logs/sec using UDP. If I increase the rate, logs start getting dropped. I don’t know what is causing the drops, is it the application (it [...]

Coming from a decade of licensed products on the Desktop, we are now planning a switch to a SaaS (Software as a Service) platform to let customers get more affordable conditions (pay-per-use). Since our (10+ year) Desktop product is a mix of 700,000 lines of C and C++, we cannot afford to rewrite it with the ‘Web’ programming languages (C#, Java or PHP) supported by the mainstream Web servers (Apache, IIS, Nginx). The HTTP overhead [...]