## 21. Slony-I Test Bed Framework

As of version 1.1.5, Slony-I has a common test bed framework intended to better support running a comprehensive set of tests at least somewhat automatically. Older tests used pgbench (not a bad thing) but were troublesome to automate because they were set up to spawn each slon in an xterm for the user to watch.

The new test framework is mostly written in Bourne shell, and is intended to be portable to both Bash (widely used on Linux) and Korn shell (widely found on commercial UNIX systems). The code lives in the source tree under the `tests` directory.

At present, nearly all of the tests make use of only two databases that, by default, are on a single PostgreSQL postmaster on one host. This is perfectly fine for those tests that involve verifying that Slony-I functions properly on various sorts of data. Those tests do things like varying date styles, and creating tables and sequences that involve unusual names to verify that quoting is being handled properly.

It is also possible to configure environment variables so that the replicated nodes will be placed on different database backends, optionally on remote hosts, running varying versions of PostgreSQL.

Here are some of the vital files...

- `run_test.sh`

This is the central script for running tests. Typical usage is thus:

`./run_test.sh`

    usage ./run_test.sh testname

You need to specify the subdirectory name of the test set to be run; each such set is stored in a subdirectory of `tests`.

You may need to set one or more of the following environment variables to reflect your local configuration. For instance, the writer runs “test1” against PostgreSQL 8.0.x using the following command line:

     PGBINDIR=/opt/OXRS/dbs/pgsql8/bin PGPORT=5532 PGUSER=cbbrowne ./run_test.sh test1

`PGBINDIR`

  This determines where the test scripts look for PostgreSQL and Slony-I binaries. The default is `/usr/local/pgsql/bin`.

  There are also variables `PGBINDIR1` thru `PGBINDIR13` which allows you to specify a separate path for each database instance. That will be particularly useful when testing interoperability of Slony-I across different versions of PostgreSQL on different platforms. In order to create a database of each respective version, you need to point to an initdb of the appropriate version.

`PGPORT`

  This indicates what port the backend is on. By default, 5432 is used.

  There are also variables `PORT1` thru `PORT13` which allow you to specify a separate port number for each database instance. That will be particularly useful when testing interoperability of Slony-I across different versions of PostgreSQL.

`PGUSER`

  By default, the user `postgres` is used; this is taken as the default user ID to use for all of the databases.

  There are also variables `USER1` thru `USER13` which allow specifying a separate user name for each database instance. As always, with Slony-I, this needs to be a PostgreSQL “superuser.”

`HOST`

  By default, `localhost` is used.

  There are also variables `HOST1` thru `HOST13` which allow specifying a separate host for each database instance.

`DB1` thru `DB13`

  By default, `slonyregress1` thru `slonyregress13` are used.

  You may override these from the environment if you have some reason to use different names.

`ENCODING`

  By default, `UNICODE` is used, so that tests can create UTF8 tables and test the multibyte capabilities.

`MY_MKTEMP_IS_DECREPIT`

  If your version of Linux uses a variation of mktemp that does not generate a full path to the location of the desired temporary file/directory, then set this value.

Within each test, you will find the following files:

- `README`

  This file contains a description of the test, and is displayed to the reader when the test is invoked.

- `generate_dml.sh`

  This contains script code that generates SQL to perform updates.

- `init_add_tables.ik`

  This is a slonik script for adding the tables for the test to repliation.

- `init_cluster.ik`

  slonik to initialize the cluster for the test.

- `init_create_set.ik`

  slonik to initialize additional nodes to be used in the test.

- `init_schema.sql`

  An SQL script to create the tables and sequences required at the start of the test.

- `init_data.sql`

  An SQL script to initialize the schema with whatever state is required for the “master” node.

- `init_subscribe_set.ik`

  A slonik script to set up subscriptions.

- `settings.ik`

  A shell script that is used to control the size of the cluster, how many nodes are to be created, and where the origin is.

- `schema.diff`

  A series of SQL queries, one per line, that are to be used to validate that the data matches across all the nodes. Note that in order to avoid spurious failures, the queries must use unambiguous `ORDER BY` clauses.

If there are additional test steps, such as running EXECUTE SCRIPT, additional slonik and SQL scripts may be necessary.