GZIP压缩HTTP响应，然后再发送给客户端

Question

I have gzipped the response using filter. The data received has been compressed from 50 MB to 5 MB however, it didn't result in much saving of time. The time taken has reduced from 12 seconds to 10 seconds. Is there anything else which can be done to reduce the time period?

Initially, the data transfer over the network took 9 seconds, now it takes 6 seconds after compression and 1 sec to decompress approximately

What else can be done?

Answer 1

For the filter the possible measures are little:

• There exist different compression levels, the more compression the slower. The default or GZIPOutputStream should be fast enough.
• GZIPOutputStream has constructors with size to set.
• Then there is buffered streaming, and not doing byte-wise int read() .
• Code review for plausibility: the original Content-Length header must be removed.

For the static content:

• .bmp are a waste of space
• .pdf can be optimized when images repeat, wrt fonts.
• .docx is a zip format, so inner image files might be optimized too

For dynamic content generation:

• Fixed documents can be stored (xxxxxx.yyy.gz) with timestamp and then the generation time forfalls. Only of interest after measuring the real bottle neck; likely the network.
• The code for delivery should be fast. In general chain streams, try not to write to a ByteArrayOutputStream, but immediately to a BufferedOutputStream(original output stream). Check that the buffering is not done twice. Some wrapping streams check that the wrapped stream is an instanceof a buffered.

Production environment:

• Maybe you even need throttling (slowing down delivery) in order to serve multiple simultaneous requests.
• You may need to do the delivery on another server.
• Buy speed from the provider. Inquire from the provider, whether the througput was too high, and the provider slowed things down.