Page 290 - DCAP312_WEB_TECHNOLOGIES_II

Web Technologies-II

Notes get into a queue and keep waiting until a worker thread is freed. This generally happens when
site starts receiving much more hits than we originally planned. In that case, if we have CPU
to spare, increase the worker threads count per process.
maxIOThreads

This is default to 20 per process. On a dual core computer, there will be 40 threads allocated
for ASP.NET for I/O operations. This means at a time ASP.NET can process 40 I/O requests
in parallel on a dual core server. I/O requests can be file read/write, database operations, web
service calls, and HTTP requests generated from within the Web application and so on. So, we
can set this to 100 if our server has enough system resource to do more of these I/O requests.
Especially when our Web application downloads/uploads data, calls many external web services
in parallel.
minWorkerThreads

When a number of free ASP.NET worker threads fall below this number, ASP.NET starts putting
incoming requests into a queue. So, we can set this value to a low number in order to increase
the number of concurrent requests. However, do not set this to a very low number because
Web application code might need to do some background processing and parallel processing
for which it will need some free worker threads.
minIOThreads

Same as minWorkerThreads but this is for the I/O threads. However, we can set this to a lower
value than min Worker Threads because there is no issue of parallel processing in case of I/O
threads.
memoryLimit
Specifies the maximum allowed memory size, as a percentage of total system memory, that the
worker process can consume before ASP.NET launches a new process and reassigns existing
requests. If we have only our Web application running in a dedicated box and there is no
other process that needs RAM, we can set a high value like 80. However, if we have a leaky
application that continuously leaks memory, then it is better to set it to a lower value so that
the leaky process is recycled pretty soon before it becomes a memory hog and thus keep our
site healthy. Especially when we are using.

Reduce the size of downloads

The problem
WebPagetest is accounting for 1,425KB of data transferred. That is quite a lot.
The worst offender in GitHub’s case seems to be the Gravatar 3rd party service. Gravatar
is a popular service that allows showing a personal avatar for users of the interweb based
on their e-mail address. In the case of that GitHub page, Gravatar is loading 34 images for
a total of 500KB. That is more than a third of the payload.
The second worst offender is the host called camo.githubapp.com. It seems to be serving
2 images in our example. At first, was a bit puzzled about that host as I could not quite
figure out why GitHub was serving directly 2 images worth 500KB (that is another third
of our total payload) instead of using their CDN. After a bit of research I found the Camo
project. GitHub is enforcing SSL for every page. When GitHub users write comments and
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