If you need to configure Zato for Oracle DB connections and you want to ensure the highest performance possible, this is the post which goes through the process step-by-step. Read on for details.

Overview

Note that Zato 3.1+ is required. The tasks involved are:

• Installing Zato
• Installing an Oracle client
• Installing cx_Oracle
• Greenifying the Oracle client
• Starting servers
• Creating database connection definitions
• Confirming the installation

Installing Zato

• Choose your preferred operating system and follow the general installation instructions - Oracle DB connections will work the same no matter the system Zato runs on

• Create a Zato environment with as many servers as required. Again, there are no Oracle-specific steps at this point yet.

Installing an Oracle client

• Download an Oracle client and install it on all the systems with Zato servers

• Add the client’s installation path to LD_LIBRARY_PATH. For instance, if the client is installed to /opt/zato/instantclient_19_3, add the following to ~/.bashrc:

  export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/opt/zato/instantclient_19_3

Installing cx_Oracle

• cx_Oracle is a Python driver for Oracle DB, it can be installed using pip, as user zato, on each Linux instance that Zato servers use:

  $ cd /opt/zato/current
  $ ./code/bin/pip install cx_Oracle
  

Greenifying the Oracle client

• This step is crucial for achieving the highest performance of SQL queries

• For each Zato server installed, open its server.conf file and find stanza [greenify]

• If there is no such stanza in server.conf, create it yourself

• Modify the stanza to greenify the libclntsh.so library - this is a library that the Oracle client ships with. For instance, if the client’s installation path is /opt/zato/instantclient_19_3, the full path to the library is /opt/zato/instantclient_19_3/libclntsh.so

• The stanza should read as below, assuming the installation path as above:

  [greenify]
  /opt/zato/instantclient_19_3/libclntsh.so=True
  

• Note that entries in this stanza are followed by =True, which is a signal to Zato that a particular library should be processed

Starting servers

• Start Zato servers

• For each, make sure that an entry such as below is saved in server logs

  INFO - Greenified library `/opt/zato/instantclient_19_3/libclntsh.so.19.1`
  

Creating database connection definitions

• Go to web-admin and create a new Oracle DB connection via Connections -> Outgoing -> SQL, as below:

• Update the newly created connection’s password by clicking Change password

• Click Ping to confirm the connectivity to the remote server

• This concludes the process, the connection is ready for use in Zato services now