Overview Default configuration for handoff may cause data loss in the OSS release of Riak TS 1.3.0. If you are using Riak TS Enterprise, you are not impacted by this bug but you SHOULD upgrade to Riak TS Enterprise 1.3.1 as soon as it is available for other handoff bug fixes.
Description In Riak TS 1.3.0, the default configuration for handoff.ip causes vnodes marked for transfer during handoff to be removed without transferring data to their new destination nodes. A mandatory change to configuration (in riak.conf) will resolve this issue. All open source users are impacted by this issue and we strongly recommend that all 1.3.0 users upgrade to 1.3.1 which will be released soon. NOTE: This is known to occur for ownership handoff and fallback transfers (hinted handoffs). Affected Users All open source users of TS 1.3.0 using riak.conf to configure their clusters are potentially impacted. To verify whether you are affected, the below command must be run on each node in your cluster: riak config effective | grep handoff.ip Affected nodes will have a handoff ip of 127.0.0.1 handoff.ip = 127.0.0.1 Impact This bug impacts vnodes that are in process of handoff. Handoff data will be looped back to the source node during ownership handoff rather than being transferred to the destination node. Once ownership handoff is completed the data is removed from the source node. In the event of significant ownership handoff, which can happen during cluster expansion or contraction, all replicas of an object may be lost. Data loss occurs if all replicas of an object are lost as a result of this configuration issue. Replica loss can be triggered by cluster membership changes or other Riak cluster activity that triggers handoff behavior. Data loss is mitigated as long as at least one replica still exists and the below steps are followed. Mitigation You can immediately mitigate the issue by setting transfer limit to zero across the cluster by issuing the following on any node: riak-admin transfer-limit 0 Then configure handoff.ip in riak.conf to an external IP address or 0.0.0.0 on all nodes. Perform a rolling restart <http://docs.basho.com/riak/kv/2.1.4/using/repair-recovery/rolling-restart/> of Riak across your cluster to activate the new setting. For additional repair work, you will need to have Riak TS 1.3.1 or higher installed across your cluster. The advisory can be found on our Product Advisories page at https://docs.basho.com/community/productadvisories/130-dataloss/ Let us know if you have questions. -- Seema Jethani Director of Product Management, Basho <http://basho.com> 4083455739 | @seemaj <http://twitter.com/seemaj>
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