This article lists improvements in Neverfail Heartbeat version 4.5.
Neverfail Heartbeat version 4.5 now includes Data Rollback Module.
Data Rollback Module
Operating in conjunction with Microsoft's Windows Volume Shadow Copy Service (VSS), Data Rollback Module provides rapid and simple application restart using data from defined earlier points in time.
Although applications such as Exchange and SQL Server can recover from certain kinds of system crashes or failures, they are still vulnerable to corruption from virus infection, or from human error (such as a user inadvertently deleting a database table).
Insurance against such corruption can be provided by a means of restoring the application to a previous state. While this ability is already provided to some degree by recovery from a tape-backup, Neverfail Data Rollback Module offers the following advantages:
- simple automated backup procedure with flexible scheduling
- minimum interval of only 15 minutes between backups, allowing fine granularity when selecting data to restore
- on-demand backup of either active or passive server
- simple automated 'one-click' rollback operation
Data Rollback Module is available for:
- Microsoft Exchange 2003 SP1 on Microsoft Windows Server 2003 Service Pack 1
- Microsoft SQL Server 2000 SP3a/SP4 on Microsoft Windows Server 2003 Service Pack 1
Maintenance fixes and enhancements
Neverfail Heartbeat release V4.5 offers improved system reliability and performance over previous versions of the software. Improvements and changes are detailed by component below:
1. Improved handling of illegal file filters.
In previous versions of Neverfail Heartbeat, it was possible under certain circumstances for the automated filter discovery mechanism to build a filter with a double backslash in the path. This filter syntax is not accepted by Neverfail Heartbeat, which would reject the malformed filter altogether. This behaviour has been modified so that Neverfail Heartbeat can correct the syntax and accept the filter.
2. Improved system performance and stability under heavy load.
3. Handling of an IllegalStateException has been improved and made more robust.
4. Neverfail Heartbeat operational statistics periodically dumped into the NFLog.
5. Neverfail Heartbeat will now only fire one HBStoppedEvent when the Missed Heartbeat limit is exceeded.
6. Application Module Configuration GUI - rejection of zero poll interval.
In previous versions of Neverfail Heartbeat, it was possible to enter a value of zero for the Service or Performance Attribute poll interval in the Application Module Configuration GUI. This is now prevented.
7. Application Module Configuration GUI - default service recovery actions.
The default series of recovery actions for protected application services is now (1) restart, (2) restart and (3) restart. Auto-switchover or other custom actions may still be configured by a system administrator where appropriate.
8. The backup phase of installation is now more robust.
9. New Data Rollback Module status and configuration panels allow comprehensive control over shadow creation, maintenance and Rollback operations.
Comms Manager Component:
10. A trace will now be made if Neverfail Heartbeat cannot resend data.
11. Hardware ID and Licensing mechanism is now more robust.
Online help and documentation:
12. Neverfail Heartbeat Online Help has been revised and updated, and the help text in the Server Configuration Wizard has been subject to some minor revisions.
13. The Reference Guide (which is now included in the root of the downloadable Neverfail Heartbeat zip file) has been expanded and updated to cover Data Rollback Module operations.