This documentation describes usage of Jack server 1.3-a11.

Jack server

The Jack server's goal is to handle a pool of Jack compiler instances in order to limit memory usage and benefit from already warm instances.

Setup for Mac OS

Jack server requires initial setup on Mac OS:

  • Install MacPorts from macports.org
    Make sure that /opt/local/bin appears in your path before /usr/bin. If not, please add the following to your ~/.bash_profile file (If you do not have a .bash_profile file in your home directory, create one):
    $ export PATH=/opt/local/bin:$PATH`
  • Get curl package from MacPorts:
    $ POSIXLY_CORRECT=1 sudo port install curl +ssl

Installing the server

Jack server is automatically installed and started by Android build. If you need to do the installation manually use:

    $ jack-admin install-server <launcher.jar> <server.jar>

Starting the server

You may need to start the Jack server manually.
Use jack-admin start-server.

Client info

The client is a bash script simply named jack.
It can be configured in $HOME/.jack-settings

.jack-settings file

This file contains script shell variables:
SERVER_HOST: IP address of the server
by default: SERVER_HOST=localhost.

SERVER_PORT_SERVICE: Server service TCP port number. Needs to match the service port number defined in $HOME/.jack-server/config.properties on the server host (See Server info below)
by default: SERVER_PORT_SERVICE=8076.

SERVER_PORT_ADMIN: Server admin TCP port number. Needs to match the admin port number defined in $HOME/.jack-server/config.properties on the server host (See Server info below)
by default: SERVER_PORT_ADMIN=8077.

SETTING_VERSION: Internal, do not modify.

Server info

The server is composed of 2 jars named jack-server.jar and jack-launcher.jar.

Check Admin section to know how to install and administrate the Jack server.

The server can also be configured in $HOME/.jack-server/config.properties.

config.properties file

It contains Jack server configuration properties.
Modifications to those settings are taken into account after restarting the server.
Description with default values follows:

jack.server.max-service=<number>
Maximum number of simultaneous Jack tasks. Default is 4.

jack.server.max-jars-size=<size-in-bytes>
Maximum size for Jars, in bytes. -1 means no limit. Default is 100 MiB.

jack.server.time-out=<time-in-seconds>
Time out delay before Jack gets to sleep. When Jack sleeps, its memory usage is reduced, but it is slower to wake up. -1 means "do not sleep". Default is 2 weeks.

jack.server.service.port=<port-number>
Server service TCP port number. Default is 8076. Needs to match the service port defined in $HOME/.jack-settings on the client host (See Client section).

jack.server.admin.port=<port-number>
Server admin TCP port number. Default is 8077. Needs to match the service port defined in $HOME/.jack-settings on the client host (See Client section).

jack.server.config.version=<version>
Internal, do not modify.

Server logs

Server logs can be found by running jack-admin server-log. Default location is $HOME/.jack-server/logs/.

Admin

The jack-admin bash script allows to install and administrate the Jack server. Here are some commands:

$ jack-admin help
Print help.

$ jack-admin install-server jack-launcher.jar jack-server.jar
Install the Jack server.

$ jack-admin uninstall-server
Uninstall the Jack server and all components. You should ensure that the Jack server is not running before uninstalling.

$ jack-admin list jack
List installed versions for Jack.

$ jack-admin update jack jack.jar
Install or update a Jack jar.

$ jack-admin start-server
Start the server.

$ jack-admin stop-server
Stop the server after the last compilation is complete.

$ jack-admin kill-server
Kill the server process immediately, interrupting abruptly ongoing compilations.

$ jack-admin list-server
List Jack server processes.

$ jack-admin server-stat
Print various info about the server and the host.

$ jack-admin server-log
Print log pattern.

$ jack-admin dump-report
Produce a report file that can be used to file a bug.

Transitioning from server 1.1 (e.g. Marshmallow) to server 1.3 (e.g. N)

The old Jack server used a $HOME/.jack configuration file. It has now replaced by a $HOME/.jack-settings and a $HOME/.jack-server/config.properties. If those new files do not exist, run jack-admin start-server and they will be created. If you had custom settings in your $HOME/.jack, here's how to adapt those.

SERVER_PORT_SERVICE=XXXX
Replace with SERVER_PORT_SERVICE=XXXX in $HOME/.jack-settings and jack.server.service.port=XXXX in $HOME/.jack-server/config.properties.

SERVER_PORT_ADMIN=YYYY
Replace with SERVER_PORT_ADMIN=YYYY in $HOME/.jack-settings and jack.server.admin.port=YYYY in $HOME/.jack-server/config.properties.

SERVER_NB_COMPILE=N
Replace with jack.server.max-service=N in $HOME/.jack-server/config.properties.

SERVER_TIMEOUT=ZZ
You can replace with jack.server.time-out=ZZ, but it is recommended to keep the default setting of "7200" (2 hours).

Other settings in the $HOME/.jack configuration file do not need to be copied. You should still keep your $HOME/.jack configuration file for the old Jack server because both server versions can run simultaneously.

Troubleshooting

Below you'll find some ways to solve some troubleshooting. If you don't find a solution, file a bug and attach the file produced by jack-admin dump-report.

If compilation fails on No Jack server running

See Starting the server above.

If your computer becomes unresponsive during compilation:

You can improve the situation by reducing the number of jack simultaneous compilations by editing your $HOME/.jack-server/config.properties and changing jack.server.max-service to a lower value and then restarting the server.

If you experience Jack compilations failing on Out of memory error.:

You can improve the situation by reducing the number of jack simultaneous compilations by editing your $HOME/.jack-server/config.properties and changing jack.server.max-service to a lower value and then restarting the server.
If this is not enough, you may change the arguments used to start the server jvm and force a greater maximum Java heap size ("-Xmx"):

  • Stop the server using jack-admin stop-server, then:
  • If you start the server manually:
    JACK_SERVER_VM_ARGUMENTS="-Xmx2g -Dfile.encoding=UTF-8 -XX:+TieredCompilation" jack-admin start-server
  • If you use the jack server in the android tree then
    export ANDROID_JACK_VM_ARGS="-Xmx2g -Dfile.encoding=UTF-8 -XX:+TieredCompilation"
    and restart your build command.

If you have trouble starting the server

This may mean that TCP ports are already in use on your computer. You can try modifying the ports both in your client and server configurations. See the Server info and Client info sections. If it doesn't solve the problem, please report and give us additional information by:

  • Attaching your compilation log.
  • Attaching the file produced by jack-admin dump-report

If your commands fails on

Failed to contact Jack server: Problem reading<your home>/.jack-server/client.pem

This may mean that your server never managed to start, see If you have trouble starting the server above.

If your compilation gets stuck without any progress

Please report and give us additional information by attaching the file produced by jack-admin dump-report.
Then restart the server by issuing commands jack-admin kill-server; jack-admin start-server