SVN MultiSite Plus Release Notes

Release: Build: 5041

Tuesday 3rd September, 2013

This latest update for WANdisco's SVN MultiSite Plus adds a new version of the installer, a notification system plus a number of bug fixes:

New Features

Introduced a notification system that allows system administrators to set up automated alert emails. The system is broadly user-configurable so that administrators can created their own triggers and message content. Set up the notifications by logging into the SVN MultiSite Plus admin UI and go to the Settings tab. (NV-1404)

The installer is now provided without Apache included in the bundle, for customers who use a specific version or install to a non-standard location. It also adds support for SSL encryption, although currently these settings can't be modified after installation. (NV-1954)

Issues Fixed

We've consolidated our API code so that the old end point for inducting a new node has been removed. The old "ApplicationResource" end point should no longer be used. Instead use the new "NodeResource" end point. NV-1957

Improved the performance and stability of the emergency reconfiguration tool. In particular, the process of reconfiguration better handles the loss of a node in 2-node replication group so that that the remaining node will continue to operate in a single-node replication group. (NV-1445)

We've now restricted the use of certain special characters within the admin UI. It is now not possible to use the following characters in entity names:
Forward slash /
Question mark ?
Equals sign =
Ampersand &
Semicolon ;
Hash #
(NV-1817)

Known issues (reported in Build 4563) that are now fixed:

Fixed: We have fixed an issue affecting 2-node replication groups; previously the commit would fail if one node would be offline or unreachable. Now the commit will succeed if the remaining node is a tie-breaker.

Fixed: a minor error in the talkback script that caused two process checks to fail. (NV-1824)

Fixed: an issue where edits made (but not applied) on a repository settings screen persist if the changes are not cancelled, i.e. if you close the window or navigate away. (NV-1833)

Fixed: The menu for selecting node type is not yet fully context driven so that it is currently possible to select a node type that is not actually available as it is not compatible with the existing setup. (NV-1853)

Fixed: We've fixed a problem where by running an emergency reconfiguration could result in dashboard tasks all showing as "Unknown Task Type". (PLAT-47)

Fixed: Induction of a new node following an emergency reconfiguration of the inductor node will cause the routes to be set incorrectly, so while the new node will know about the other member nodes, they won't know about it. (PLAT-14)

Fixed: Disconnecting a node from a replication group will cause the node to lose all replication group information. We'll be improving the UI messaging around this in the next release. (NV-1815)
Fixed: The "Task" endpoint which would allow the retrieval of MultiSite's internal tasks is currently not available through the public API. This should be available again in the next release. (NV-1761)

Known Issues

The apparent inconsistency in the size of repositories is the result of using different measuring methods. SVN MultiSite's UI measures repositories by the total byte count. This will not match the apparent sizes shown using different measuring methods, such as reading the size of allocated blocks. (NV-696)

Inducting a new node using an incorrect locaion ID caused the connection to fail in a manner that is not graceful - the node is listed as "connection pending" and is stuck. If the problem occurs it will block the new node from being inducted to a different node. (NV-1827)

We continue to investigate various browser compatibility issues with Internet Explorer 8. Although SVN MultiSite Plus's Admin UI is broadly functional in IE8, we're aware that some secondary features don't work. We'll continue to investigate this issue. (NV-1702)

Release: Build: 4563

Tuesday 6th August, 2013

This latest update for WANdisco's SVN MultiSite Plus adds a number of important new functions, along with various fixes and improvements:

New Features

Wider operating system support
SVN MultiSite Plus can now be installed across a wider range of Linux distributions. (NV-1580)

Added Disk Monitoring
We've added a system for monitoring the server's available disk space. Now administrators can receive automated emails should disk space get low, and if disk space becomes critical the system will safely shut the server down to prevent potential data corruption. You can read more in the online Admin Guide: Resource Monitor (NV-1299)

We've improved the way that SVN MultiSite Plus handles co-ordinated actions. It's now possible to perform synchronised stops across all nodes or on a per node basis . There remains a limitation in that any repositories that are flagged as Local Read-only (LRO) then it won't be possible to complete the stop in a synchronized manner.(NV-1579)
Removing nodes from replication groups There is now a facility for removing nodes from a replication group. It was previously necessary to recreate the entire replication group if you needed a change to its membership. You can read more in the online Admin Guide: Removing a Node from a Replication Group [NV-1121]

Recovery Process
We've added a mechanism for transactional recording of a 'map of the world' for each node which includes node settings, membership, DSMs and replication group details. [NV-1578]

Talkback troubleshooting tool
Now included as a Talkback script that can be automatically or manually run in order to capture information that can assist administrators and WANdisco's support team in identifying and fixing problems. You can read more about talkback in the online Admin Guide: Running Talkback [NV-397]

Version Check
Nodes will now routinely check that the other nodes that it connects to are running the same version of SVN MultiSite. (NV-1068)

Known Issues

We have fixed an issue affecting 2-node replication groups; previously the commit would fail if one node would be offline or unreachable. Now the commit will succeed if the remaining node is a tie-breaker. (NV-1824)

Fixed a minor error in the talkback script that caused two prcess checks to fail. (NV-1824)

The apparent inconsistency in the size of repositories is the result of using different measuring methods. SVN MultiSite's UI measures repositories measures the total byte count of repositories. This will not match the apparent sizes shown using different measuring methods, such as reading the size of allocated blocks. NV-696

We've fixed an issue where edits made (but not applied) on a repository settings screen perist if the changes are not cancelled, i.e. if you close the window or navigate away. (NV-1833)

The menu for selecting node type is not yet fully context driven so that it is currently possible to select a node type that is not actually available as it is not compatible with the existing setup. (NV-1853)

When inducting a new node with an incorrect location ID, the new node's connection failure is not currently handled gracefully - by listing the new node under connection pending, allowing for the induction to be cancelled. If the problem occurs it will block the new (inductee) node from being inducted through a different inductor node. (NV-1827)

Running an emergency reconfiguration can block further nodes from being added to the replication group. (NV-1804)

We've fixed a problem where by running an emergency reconfiguration could result in dashboard tasks all showing as "Unknown Task Type". (PLAT-47)

Induction of a new node following an emergency reconfiguration of the inductor node will cause the routes to be set incorrectly, so while the new node will know about the other member nodes, they won't know about it. (PLAT-14)

Disconnecting a node from a replication group will cause the node to lose all replication group information. We'll be improving the UI messaging around this in the next release. (NV-1815)
The "Task" endpoint which would allow the retrieval of MultiSite's internal tasks is currently not available through the public API. This should be available again in the next release. (NV-1761)

We continue to investigate various browser compatibility issues with Internet Explorer 8. Although SVN MultiSite's Admin UI is broadly functional in IE8, we're aware that some secondary features don't work. We'll continue to investigate this issue. (NV-1702)

Release: Build: 4098

Monday 20th June, 2013

This release focused on: improving the stability of the installer, making available some new node types and expanding supported distributions to include RHEL5 and SuSE11 - support was previously limited to RHEL6).

A list of the most important changes is provided below:

New Features

Synchronized Stop
The Synchronized Stop is used to stop replication between repository replicas, it can be performed on a per-repository basis or on a replication group basis (where replication will be stopped for all associated repositories). Stops are synchronized between nodes using a 'stop' proposal to which all nodes need to agree. So that while not all nodes will come to a stop at the same time they do all stop at the same point. See the Admin Guide: 19. Performing a Synchronized Stop

New Node Types
We've introduced the following types of nodes, providing administrators with additional flexibility while designing replication groups:
- Passive only: A node on which repositories recieve updates from other sites, but don't permit any changes to it's replicas from Subversion clients - effectively making its repositories read-only. Passive nodes are ideal for deployments that are looking for hot-backup
- Passive voter: A passive node that also takes part in the vote for transaction ordering agreement.
- Voter only: A Voter-only node doesn't store repository data, it's only purpose is to accept transactions and cast of vote on transaction ordering. Voter-only nodes add resilience to a replication group as they increase the likelyhood that enough nodes are available to make agreement on transaction ordering. Voter only nodes don't cache transaction history or repository changes - they can play no part in a recovery scenario.
Improved Installer
We've improved the installer's stability and now better checking of the server for existing Subversion installations. (NV-1582)

Issues Fixed

Further fixes and refinements to the public REST API.
Read more about SVN MultiSite Plus's API (NA-5890)

Fixed an issue that in some situations would cause a NullPointerException on clicking the Node Reconfigure button on the Nodes table screen. (NV-1612)

Known Issues

Although SVN MultiSite Plus's browser-based Admin UI is compatible with Internet Explorer 8 there are a number of Java script and rendering problems that make some non-essential features such as dashboard widgets unusable. We're investigating these issues and will apply our best efforts in order to overcome them. (NV-1702)