Compression is enabled by default for the Genero Application Server. You can disable
compression on selected resources or for the entire Genero Application Server.
Files managed by the Genero Application Server can be compressed to reduce the size of
files sent to the User Agent. The files can be compressed by hand and deployed in the
GAS, but it is also possible to configure the GAS to compress application files on the
fly.
Compression is configured in the $FGLASDIR/etc/imt.cfg file. This file lists
the type of resources that can be compressed. GAS automatically compresses the files
with the file extensions listed in imt.cfg.
When does compression take place?
Compression takes place at:
- Installation time
- At application deployment with Genero Archive
- At runtime, when communication files, i.e. HTTP request/response type files that do
not need to be saved on disk, are exchanged between GAS and applications. These are
compressed on the fly.
- At runtime when files on disk are requested by applications.
Note: At runtime, the GAS
checks the
imt.cfg to see if the requested file is expected to be
a compressed file. If the compressed file is not up to date or is missing, the GAS
performs the following:
- It compresses the requested resource on the fly and sends a compressed
result.
- A warning is displayed in the GAS log (see Logging) if the compressed file is out of date or is
missing. (To prevent these warnings, you will need to update compressed files.
You can manually generate the compress files (.gz) with the gasadmin
-z command or using another appropriate compression utility
command).
- You can compress static files as required using the gasadmin -z
command, see gasadmin
tool.
Enabling and disabling GAS compression
Both the
gasadmin
-z compression command and the GAS use the
imt.cfg file to
identify the resources that can be compressed.
imt.cfg
sample:
# [-] Internet media type Extension
# The optional '-' sign at the beginning can be used to explicitly
# disable compression when sending resources
# Example: see below application/java-archive
#
# Uncomment the following line to completely disable compression
# gas:disable-compression
application/andrew-inset ez
- application/java-archive jar
application/font-woff woff
application/mac-binhex40 hqx
application/mac-compactpro cpt
application/msword doc
...
To disable compression for a specific resource, place a '-' sign at the beginning of that
resource in the listing. For
example:
- application/java-archive jar
To disable all compression by the Genero Application Server, uncomment the
gas:disable-compression entry in the file.
Compression enabled (entry is a comment;
default):
# gas:disable-compression
Compression disabled (entry is not a
comment):
gas:disable-compression