Release Notes for Couchbase Server 7.6

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      New Features and Enhancements

      For detailed information on new features and enhancements, please see What’s New in Version 7.6.

      Deprecated and Removed Features and Platforms

      • The following platforms are still supported, but deprecated in Couchbase Server 7.6:

        • Amazon Linux 2 LTS x86 & ARM

        • Microsoft Windows Server 2019

        • Ubuntu 20.04 LTS x86 & ARM

        • MacOS 12 (Monterey) x86 & ARM

      • We are removing these platforms from support (they are already deprecated):

        • Debian Linux 10 (Buster)

        • MacOS 11 (BigSur)

      • Removed support for TLS 1.0 and 1.1. Both the standards bodies and Couchbase have already deprecated these versions due to their lack of security. (MB-58045)

      • The cbbackup and cbrestore utilities have been removed from Couchbase Server 7.6. The same functionality is provided in cbbackupmgr.

      • Removed support for password-less buckets.

      • Customers using the Couchbase yum or apt repositories to install Couchbase Server on Linux must ensure they are using the latest version 1.0-13 of the couchbase-release meta-package prior to upgrading to Couchbase Server 7.6.0 or later. To check which version you currently have installed:

        • On RPM-based systems: rpm -q couchbase-release (should return couchbase-release-1.0-13.noarch)

        • On Debian-based systems: dpkg -s couchbase-release|grep Version (should return Version: 1.0-13)

        If you have a version lower than 1.0-13 installed, please follow the instructions for Installing Couchbase Server on Red Hat or Installing Couchbase Server on Ubuntu and Debian to install the latest couchbase-release meta-package.

      Fixed Issues

      This release contains the following fixes.

      Cluster Manager

      Issue

      Description

      Resolution

      MB-60568

      CPU utilization rate may be incorrect in a VM.
      When running a VM on a XEN hypervisor, stats were computed using the number of processors configured for the entire system.

      Stats now use the number of logical processors online on the system. This correction affects the following stats:

      • sys_cpu_host_cores_available

      • sys_cpu_utilization_rate

      • sys_cpu_host_utilization_rate

      Data Service

      Issue Description Resolution

      MB-58088

      When the client sends an unlock request for a document that is not locked, the server returns a "temp fail" error code. This causes the client to retry until the operation times out.

      The server returns a new "not locked" error code.

      MB-59060

      When the client sends an unlock request for a document that is not cached in Full Eviction mode, the server returns a "temp fail" error code, even if the document is stored on disk. This causes the client to retry until the operation times out.

      The metadata of locked documents are kept in the hashtable. The server returns a new "not locked" error code if the document exists, "not found" otherwise.

      XDCR

      Issue Description Resolution

      MB-58671

      Erroneous network conditions could lead to checkpoint manager slow at stopping.

      Ensure the checkpoint manager stops, even if it has trouble starting due to network issues.

      MB-59233

      In low-priority replications, it is possible for a Data Service stream to end temporarily and for XDCR to not handle it correctly. This will lead to a hung replication.

      Now, XDCR restarts the pipeline if a data service stream ends.
      This ensures replication continues.

      MB-59320

      Race condition in starting and stopping XDCR source nozzle could lead to a memory leak

      Fixed the race condition

      MB-59416

      If the Bandwidth throttler is used, race condition may occur during pipeline shutdown where the Out nozzle is unable to exit

      Fix race condition during shutdown to ensure out nozzle closes properly.

      MB-59499

      In a slow running backfill replication, XDCR could be too aggressive in restarting pipelines.

      Ensure XDCR does not restart backfill pipelines if some progress is observed periodically.

      MB-59669

      If a replication is idle without mutations, XDCR is unable to detect that a target bucket failover occurred.

      Ensure target-side failover detection takes place, even if the source has no incoming mutations

      MB-59745

      When a target document is locked, and a non-optimistic LWW replication is taking place, XDCR will retrieve a "locked CAS" of maxUint. This will cause the source mutation to lose, and lead to scenarios where the mutation is not replicated, even if it should have won conflict resolution.

      XDCR will retry conflict resolution for the duration that the document is locked in pessimistic replication. This will ensure that a valid CAS is used for source-side conflict resolution.

      Query Service

      Issue Description Resolution

      MB-39484

      SQL++ will not support operations on legacy buckets without password specification.

      Users must authenticate first to connect to the query service and execute any SQL statement.

      MB-58648

      Observed a memory leak with multiple executions of the same UDF function.

      Fix the condition whereby UDF functions are being re-loaded into cache from storage every time the function is executed.

      MB-59501

      The system catalog allows users to see items without RBAC authentication or authorization.

      Valid RBAC permissions are required to query the system catalog, and to view items stored in the catalog.

      Index Service

      Issue Description Resolution

      MB-59138

      The system did not support nested flattened array indexes when an entry was missing in nested arrays.

      The system now correctly expands null or missing entries for nested arrays.

      Search Service

      Issue Description Resolution

      MB-57657

      When running non-analytic queries from SQL++ there was an expectation to use the keyword analyzer. If the user specified any other analyzer, then the analyzer expectation was not met, leading to the error: No index available on keyspace.

      The non-analytical queries are:

      • TermQuery

      • PhraseQuery

      • MultiPhraseQuery

      • FuzzyQuery

      • PrefixQuery

      • RegexpQuery

      • WildcardQuery

      This restriction has been lifted in 7.6.0.
      The user will now be able to run queries via SQL++ without having to run the keyword analyzer.

      MB-59858

      When a Search index name is too long, the index silently fails to ingest documents.

      The UI will now flag instances where the chosen index name is too long.

      MB-60718

      Index alias queries not returning cumulative (duplicate) results from its targets.

      The fix prevents cyclic lockups within aliased index targets (aliases with the same targets pointing to each other to an infinite depth).
      The service also de-duplicates index targets.

      Tools

      Issue Description Resolution

      MB-57988

      cli should allow modifying existing collection’s maxTTL

      The Couchbase CLI has been extended to allow the maxTTL (maximum time-to-live) to be modified for a collection.

      Known Issues

      This release contains the following known issues.

      Tools

      Issue Description Workaround

      MB-59352

      When the Load Metadata from File option is selected, the Couchbase Server UI does not disable two options that can’t be used: Validate metadata using trusted fingerprints and Verify Remote Peer. These two options are irrelevant during metadata upload. Selecting them will have no impact on the process.

      NA

      MB-60062

      When the auto-failover timeout setting is set to fewer than 5 seconds (the recommended minimum), you can no longer modify any cluster settings using the Couchbase Server UI.

      Modify settings using the Nodes and Clusters REST API. For more information on the auto-failover settings, see the documentation.

      MB-61076

      Scheduled merges (i.e. merges that are performed in a task in a plan) do not run. Note that backups scheduled for the merge are left in place so no data is lost.

      Merge backups manually using the UI or using the API.