5.1 Lower stack level products, Java, WebSphere Application Server, and web servers5.1.1 WebSphere Application Server and IBM Java upgrades5.1.2 Thread pools and sizings5.1.3 HTTP sessions5.1.4 Operating system maintenance5.1.5 Virtualization5.2 Security and LDAP connections5.2.1 Default configuration5.2.2 Default users and groups5.2.3 LDAP5.2.4 User and group synchronization5.2.5 IBM BPM database and custom data sources5.3 External integrations