==================================================
How to do common tasks from the Linux command line
==================================================

This document is out of date, see :ref:`Solutions Backend Programs`.

The following describes how to use the backend programs installed on
``hill301-2.math.rutgers.edu``.  The backend programs are installed in
the directory ``/data`` on this computer, and all users in the Unix
group ``math-solutions`` have permissions to use this directory.
Solutions team members are encouraged to create their own
subdirectories under ``/data`` for testing, and use the program
``admin/deploy-backend.sh`` to initialize it (for now, ask Anders).
One (and only one) team member should configure ``crontab`` to run the
backend programs automatically, see points (A) and (B) below.  Other
team members can use the :ref:`Commands requiring cronenv.sh` to carry
out various tasks and for testing.  The examples in this document use
the directory ``/data/solutions``, but it could be ``/data/whatever``.


(A) Change the server and database used by the crontab programs
===============================================================

Edit the file /data/solutions/etc/crontab to change the environment
variables LIVEHOST and LIVEDB, then install as new crontab file::

   cd /data/solutions/etc
   vim crontab
   crontab < crontab


(B) Disable or change frequency of crontab programs
===================================================

Disable daily backup of database::

   cd /data/solutions/etc
   mv cron.daily/70backup cron.disable

Re-enable backup::

   cd /data/solutions/etc
   mv cron.disable/70backup cron.daily

Change frequency of CSS download to every hour::

   cd /data/solutions/etc
   mv cron.4hours/50css cron.hourly


=============================
Commands requiring cronenv.sh
=============================

For the following things to work, first make sure to set the same
environment variables as the programs started by cron will see::

   source /data/solutions/bin/cronenv.sh

For example, this sets the variable ``$SOLHOME`` to
``/data/solutions``.


(1) Check the log files
=======================

Either look at them in the directory $LOG::

   less $LOG/formdata.log

Or use the program status.sh (in ``$SOLHOME/bin``) to read a summary::

   status.sh | less


(2) Run a crontab program immediately on LIVE database
======================================================

Run form download::

   cd $SOLHOME/etc/cron.15min
   ./30formdata

One-line version::

   $SOLHOME/etc/cron.15min/30formdata

Run CSS download::

   $SOLHOME/etc/cron.4hours/50css


(3) Run a crontab program on test database
==========================================

Change these environment variables to reflect your wishes::

   export LIVEHOST=math-sql2.sas.rutgers.edu
   export LIVEDB=mathdb_test1

Then do the same as in (2)::

   $SOLHOME/etc/cron.15min/30formdata


(4) Connect to the database servers
===================================

The following command connects to the test MySQL server::

   mysql --defaults-file=$SOLSECURE/mathdb.cnf \
         --host math-sql2.sas.rutgers.edu

You can see the hostname of the server you connected to with this
SQL command::

   select @@hostname;


(5) Restore database backup
===========================

Restore the (compressed) backup file mathdb-180910-231311.dump.gz to
the database mathdb_test1 on math-sql2.sas.rutgers.edu as follows.

First delete all tables in the database::

   mysql --defaults-file=$SOLSECURE/mathdb.cnf \
         --host math-sql2.sas.rutgers.edu

   MariaDB [(none)]> drop database mathdb_test1;
   Query OK, 104 rows affected (0.16 sec)

   MariaDB [(none)]> create database mathdb_test1;
   Query OK, 1 row affected (0.00 sec)


Then upload the backup database::

   cd $SOLHOME/backup
   zcat mathdb-180910-231311.dump.gz \
     | mysql --defaults-file=$SOLSECURE/mathdb.cnf \
             --host math-sql2.sas.rutgers.edu \
	     --database mathdb_test1

Note: backspace "``\``" continues the command on next line in bash.