Setting up LDAP failover for Websphere Application Server

As you may know LDAP is crucial to Websphere Application Server (WAS) when using it for IBM Connections so it makes good sense to configure failover for LDAP. If the LDAP server becomes unavailable you can no longer log in (actually you can’t even log into ISC – see Websphere Application Server Security – make sure file based auth continues if federated repository is unavailable) and WAS can have a hard time reconnecting to the LDAP. Failover is set up using either the ISC Federated Security UI or by editing wimconfig.xml directly (or using wsadmin commands). Using wimconfig.xml have some advantages as you can set some additional parameters. The screenshot below shows a secondary LDAP server added to the ISC.

Editing wimconfig.xml (see the wim/config-subdirectory of the cell configuration directory e.g. c:wasprofilesdmgrconfigcellsLCCell01wimconfigwimconfig.xml) is easy as well. You simply add an additional LDAP server to the config:ldapServers tag as shown below. The parameters in bold can be used to make sure that WAS return to the primary LDAP server (first listed) and optionally what the poll time should be (in minutes).

<config:ldapServerConfiguration primaryServerQueryTimeInterval="15"
   <config:ldapServers authentication="simple" bindDN="cn=LDAP User,o=Example"
      bindPassword="{xor}removed :)" connectionPool="false" connectTimeout="0"
      derefAliases="always" referal="ignore" sslEnabled="false">
      <config:connections host="" port="389"/>
      <config:connections host="" port="389"/>

Full info in the info center under Primary and secondary LDAP server failover.

Looking up a datasource from an IBM Connections event handler

For a customer project I’m working on these days I’m writing an event handler for IBM Connections Profiles to integrate two profile systems in real-time using the IBM Connections 4.0 Event SPI. Pretty powerful stuff in case you’ve never looked into it.

In IBM Connections an event handler is basically just a Java bean which you register in events-config.xml to be called when certain events occur such as a profile being updated, the photo set, the photo removed etc. In this event handler I needed to contact the Profiles database which should be easy as it’s registered in JNDI in Websphere Application Server. I couldn’t however use the usual java:comp/env/jdbc/profiles resource reference as there’s no J2EE deployment description for the event handler and hence the naming context hasn’t been mapped for me.

But with Websphere Application Server being the all-purpose application server that it is, I was able to find a way to make it work anyway. It turns out that all resources are mapped into a JNDI namespace using their cell and cluster prefix as well (I was able to deduce it from the “Example: Looking up an EJB home or business interface with JNDI” page).

So to look up the jdbc/profiles data source from the Cluster1-cluster scope I simply use the following. Sweet.

try {
   InitialContext ctx = new InitialContext();
   DataSource ds = (DataSource)ctx.lookup("cell/clusters/Cluster1/jdbc/profiles");
} catch (NamingException e) {
   // unable to lookup data source

Lotus Connections teaches you how to scale images in Java

Lotus Connections is a little bit screwy when it comes to profile pictures IMHO as they are being forced to be square in Profiles (115×115 pixels). In profiles search results however they are scaled to 55 pixel in width and height is automatic…

In my mind portrait pictures are rectangular and not square.

Yesterday this gave me some grief as I was at a customer where I had to write Java code to import pictures in the PHOTO table of the Lotus Connections PEOPLEDB database. The actual importing the pictures into the database is easy using JDBC but the pictures showed up wrongly in Lotus Connections as they were rectangular (200 x 133 pixels). They clearly had to be scaled but how – clearly not manually!

As with many other things you are gifted with Java as it already contains all the pieces you need to scale pictures. I quickly found some sample code on Google to use java.awt for the resizing. The solution was to

  1. Scale the source image from 200 x 133 pixels to 115 x 76 pixels to keep the aspect ratio
  2. Create a new blank white image sized 115 x 115 pixels
  3. Place the resized source image on top of the white image centered
  4. Upload the resulting image to the database as a byte array

Love Java!

StelsCSV v3.0 – a Fast JDBC Driver for CSV/Text Files

Unfortunately it isn’t open source and/or free but I can certainly see the uses for a JDBC driver that acts on plain text files. I cannot count the number of times I have written routines for parsing text files during migration projects. Could this be the answer. Imagine being able to simply JOIN data from different text files! Nice!! Licenses start at 109 USD.

StelsCSV v3.0 – a Fast JDBC Driver for CSV/Text Files @ JAVA DEVELOPER’S JOURNAL