Browser seems slow
There are various factors that could make the browser appear to have slow behavior. Here are suggested ways to test the browser performance.
Check network connection
Verify browser address can be found, unix command: host genome.ucsc.edu
$ host genome.ucsc.edu genome.ucsc.edu is an alias for genome.soe.ucsc.edu. genome.soe.ucsc.edu has address 22.214.171.124 genome.soe.ucsc.edu has address 126.96.36.199
Verify network path is available to the browser: ping -c 3 genome.ucsc.edu
$ ping -c 3 genome.ucsc.edu PING genome.soe.ucsc.edu (188.8.131.52) 56(84) bytes of data. 64 bytes from hgw1.soe.ucsc.edu (184.108.40.206): icmp_seq=1 ttl=43 time=170 ms 64 bytes from hgw1.soe.ucsc.edu (220.127.116.11): icmp_seq=2 ttl=43 time=170 ms 64 bytes from hgw1.soe.ucsc.edu (18.104.22.168): icmp_seq=3 ttl=43 time=170 ms --- genome.soe.ucsc.edu ping statistics --- 3 packets transmitted, 3 received, 0% packet loss, time 2000ms rtt min/avg/max/mdev = 170.361/170.370/170.378/0.007 ms
verify browser alive and well
time wget --user-agent=browserAliveTest -O- https://genome.ucsc.edu/cgi-bin/hgTracks?measureTiming=1 2>&1 | grep Overall <span class='timing'>Overall total time: 526 millis<br /></span> real 0m1.245s user 0m0.021s sys 0m0.019s
Note the Overall total time: 526 millis is the total run time of the hgTracks CGI binary
The real 0m1.2345s is the total run time of the wget command including the transmission of the html text from the hgTracks operation. This test can also be used on the http connection to see if it is any different:
time wget --user-agent=browserAliveTest -O- http://genome.ucsc.edu/cgi-bin/hgTracks?measureTiming=1 2>&1 | grep Overall <span class='timing'>Overall total time: 439 millis<br /></span> real 0m0.959s user 0m0.003s sys 0m0.012s
verify browser performance similar to web browser access
The simple wget test above only transmits the single top-level content of the html page returned from hgTracks. Your web browser will use references within that page to request more files from the browser. To simulate a complete, no cache involved, transfer of all files in the browser page, go to a work directory where the wget command can create a hierarchy of files. For example:
$ cd /dev/shm $ time wget --user-agent=browserFullPageTest \ -o browser.wget.log \ --wait=0 \ --execute="robots=off" \ --no-cookies \ --timestamping \ --level=1 \ --convert-links \ --no-parent \ --page-requisites \ --adjust-extension \ --max-redirect=0 \ "https://genome.ucsc.edu/cgi-bin/hgTracks?measureTiming=1" real 0m9.962s user 0m0.074s sys 0m0.040s $ grep Overall genome.ucsc.edu/cgi-bin/*.html <span class='timing'>Overall total time: 463 millis<br /></span>
Again, the Overall total time: 463 millis is the total run time of the hgTracks CGI binary, and the real 0m9.962s is the total time for the wget command to transfer everything. You will find a hierarchy of files in a newly created directory ./genome.ucsc.edu.
If this command is repeated, with the previous result available in ./genome.ucsc.edu, this will simulate (not perfectly) a web browser operation where the static content remains in cache and doesn't need to be transferred again. This isn't a perfect web browser simulation because this command does a HEAD operation on each access that it wants to determine if it can be cached. A web browser has other means of caching to avoid constant HEAD operation. It will occasionally, but not often.