v2.5.3 Release Notes - June 14, 2023

Fixes

Deadlock can occur on orderer startup while applying raft configuration changes from previous blocks

An ordering service node may get into a deadlock state after startup while applying raft configuration changes from previous blocks. The ordering service node would need to be restarted in order to make forward progress processing blocks. This fix ensures that the ordering service node doesn't get into a deadlock state. #4267

Dependencies

Fabric v2.5.3 has been tested with the following dependencies:

• Go 1.20.5
• CouchDB v3.3.2

Fabric docker images on dockerhub utilize Ubuntu 20.04.

Deprecations (existing)

Ordering service system channel is deprecated

v2.3 introduced the ability to manage an ordering service without a system channel. Managing an ordering service without a system channel has privacy, scalability, and operational benefits. The use of a system channel is deprecated and may be removed in a future release. For information about removal of the system channel, see the Create a channel without system channel documentation.

FAB-15754: The 'Solo' consensus type is deprecated.

The 'Solo' consensus type has always been marked non-production and should be in use only in test environments; however, for compatibility it is still available, but may be removed entirely in a future release.

FAB-16408: The 'Kafka' consensus type is deprecated.

The 'Raft' consensus type was introduced in v1.4.1 and has become the preferred production consensus type. There is a documented and tested migration path from Kafka to Raft, and existing users should migrate to the newer Raft consensus type. For compatibility with existing deployments, Kafka is still supported, but may be removed entirely in a future release. Additionally, the fabric-kafka and fabric-zookeeper docker images are no longer updated, maintained, or published.

Fabric CouchDB image is deprecated

v2.2.0 added support for CouchDB 3.1.0 as the recommended and tested version of CouchDB. If prior versions are utilized, a Warning will appear in the peer log. Note that CouchDB 3.1.0 requires that an admin username and password be set, while this was optional in CouchDB v2.x. See the Fabric CouchDB documentation for configuration details. Also note that CouchDB 3.1.0 default max_document_size is reduced to 8MB. Set a higher value if needed in your environment. Finally, the fabric-couchdb docker image will not be updated to v3.1.0 and will no longer be updated, maintained, or published. Users can utilize the official CouchDB docker image maintained by the Apache CouchDB project instead.

FAB-7559: Support for specifying orderer endpoints at the global level in channel configuration is deprecated.

Utilize the new 'OrdererEndpoints' stanza within the channel configuration of an organization instead. Configuring orderer endpoints at the organization level accommodates scenarios where orderers are run by different organizations. Using this configuration ensures that only the TLS CA certificates of that organization are used for orderer communications; in contrast to the global channel level endpoints which would cause an aggregation of all orderer TLS CA certificates across all orderer organizations to be used for orderer communications.

FAB-17428: Support for configtxgen flag --outputAnchorPeersUpdate is deprecated.

The --outputAnchorPeersUpdate mechanism for updating anchor peers has always had limitations (for instance, it only works the first time anchor peers are updated). Instead, anchor peer updates should be performed through channel configuration updates.

FAB-15406: The fabric-tools docker image is deprecated

The fabric-tools docker image will not be published in future Fabric releases. Instead of using the fabric-tools docker image, users should utilize the published Fabric binaries. The Fabric binaries can be used to make client calls to Fabric runtime components, regardless of where the Fabric components are running.

FAB-15317: Block dissemination via gossip is deprecated

Block dissemination via gossip is deprecated and may be removed in a future release. Fabric peers can be configured to receive blocks directly from an ordering service node, and not gossip blocks, by using the following configuration:

peer.gossip.orgLeader: true
peer.gossip.useLeaderElection: false
peer.gossip.state.enabled: false
peer.deliveryclient.blockGossipEnabled: false

FAB-15061: Legacy chaincode lifecycle is deprecated

The legacy chaincode lifecycle from v1.x is deprecated and will be removed in a future release. To prepare for the eventual removal, utilize the v2.x chaincode lifecycle instead, by enabling V2_0 application capability on all channels, and redeploying all chaincodes using the v2.x lifecycle. The new chaincode lifecycle provides a more flexible and robust governance model for chaincodes. For more details see the documentation for enabling the new lifecycle.