Support for Python versions 3.0 to 3.5 (inclusive) has been discontinued.
Kudu now supports a new experimental cache eviction policy named Segmented LRU (SLRU). This eviction policy helps the block cache better resist large scans that would otherwise evict frequently accessed data. (see KUDU-613).
A new experimental feature has been introduced to store LBM metadata in embedded RocksDB (see KUDU-3371).
Several minor improvements to the performance of Kudu masters and tablet servers.
The internal server-side counter for the Auto-Incrementing column is now updated during the
server’s bootstrap process (see KUDU-1945).
Tables with Auto-Incrementing column can now be backed up and restored
(see KUDU-1945).
Added /ipki-ca-cert, /ipki-ca-cert-pem, and /ipki-ca-cert-der endpoints for the embedded webserver of Kudu master to fetch the IPKI CA certificate used by a Kudu cluster.
Added client API to import JWT for client authentication (see KUDU-3472).
Added logic to detect unexpected jumps in the local/wall clock. This is enabled by default when running at Azure VM instances which are known to be prone to such events. Otherwise, this logic is disabled. For details, refer to the online documentation for --wall_clock_jump_detection and --wall_clock_jump_threshold_sec flags.
Kudu can now be built with the default system gcc/g++-7 compiler on SLES15.
Kudu can now be built on macOS 14.x (Sonoma) with XCode 15 and newer.
Added validator for the --trusted_certificate_file flag to catch misconfigurations (such as pointing to a non-existing file) early (see KUDU-3392).
Added a new metric to track per-RPC timeouts. This helps in identifying if requests to a particular RPC method timed out while being processed (see KUDU-3514).
Added a new metric for AcceptorPool’s dispatch timing. See the online documentation for the acceptor_dispatch_times metric.
Unified logging on write requests rejected by tablet servers. This helps in troubleshooting and post-mortem analysis.
Increased the backlog of listened RPC sockets up to 512. This helps in a very busy Kudu cluster when many clients attempt to connect to the cluster concurrently.
Added Cache-Control, X-Content-Type-Options, and HSTS HTTP headers into Kudu embedded webserver’s responses. For details, see the online documentation for --webserver_hsts_max_age_seconds and --webserver_hsts_include_sub_domains flags.
Introduced rpc_listened_socket_rx_queue_size and rpc_pending_connections metrics for Kudu master and tablet servers. For details, see the online documentation for the newly introduced metrics.
Updated the severity level of a few tablet-level metrics to bring them on-par with the rest of metrics having similar semantics. See changelist 35716499d for details.
Removed unnecessary memory allocation for ancient UNDO mutations. See changelist 3bdaf50b5 for details.
Apache Ranger client now accepts JVM arguments via --ranger_java_extra_args and a colon-separated list of classpaths via --ranger_jar_path (see KUDU-3503 and KUDU-3359).
Key materials for over-the-wire encryption can now be encrypted on disk without data-at-rest encryption or file-system level encryption using --tsk_private_key_password_cmd and --ipki_private_key_password_cmd (see KUDU-3448).
Maintenance operations other than DRS or MRS flush could be scheduled now even if the server is under memory pressure. Set run_non_memory_ops_prob to a value greater than 0 to enable it (see KUDU-3407).
Introduced new metrics for slow scans in tablet servers.
Buffer space limit in the Kudu Java client (KuduSession) is now configurable.
Compaction for soft-deleted tables is now disabled by default.
Several metrics have been introduced to track operations such as table creation, table deletion, alter table schema, tablet scans, tablet copy, tablet replica election, and tablet replication.
Enhanced the robustness of key retrieval from Ranger.
Kudu now runs on AArch64 Ubuntu and RedHat.
Installation of the Kudu Python package has been simplified, removing the need for a manual Cython installation; compatible versions are now automatically handled. Dependencies have been updated to support Python 2.7 and 3.6-3.10, and test files are now excluded from the final package.
Per-session write operation metrics have been added to the Kudu Python client.
Support for UPSERT IGNORE has been added to the Kudu Python client (see KUDU-3353).
The Kudu C++ and Python client examples have been added to demonstrate the utilization of the non-unique primary key feature.
Support for soft table deletion has been added to the Kudu Python client (see KUDU-3326).
Support for adding comments in ColumnSchema has been added to the Kudu Python client.
Support for immutable columns has been added to the Kudu Python client.
Kudu now supports dedicated SPNEGO keytab (see KUDU-3496).
Kudu now supports creating under-replicated tables (when the number of requested replicas is greater than the number of tablet servers) as long as consensus can be achieved (see KUDU-3452).
Tablet copying speed can now be limited (see KUDU-3447).
The maximum size of RPC messages is now configurable via the Kudu C++ client (see KUDU-3595).
Tablet-level metrics are now available in Prometheus format as well. Previously, only server-level Kudu metrics were available in Prometheus format (see KUDU-3563).
Range aware cluster rebalancer can now be run for multiple tables and against the whole Kudu cluster.
The example Kudu C++ client application now works with HMS-enabled Kudu clusters.
Addressed several CVE’s from thirdparty dependencies by upgrading them (see KUDU-3626, KUDU-3629)
Upgraded Gradle to version 7.6.4 (see KUDU-3551).
Kudu now uses x509_get_signature_info() (OpenSSL 1.1.1+) to correctly detect hash algorithms for RSASSA-PSS certificate signatures, fixing a limitation in the previous approach. (see KUDU-3663).
Fixed issue where UPDATE privilege granted by Ranger is not honored by Kudu. (see KUDU-3661).
Fixed scan issues where an unexpected predicate was introduced (see KUDU-3518).
Fixed a bug in the range-aware replica placement code where the master would crash (see KUDU-3532).
The ‘kudu table copy’ CLI tool now exits gracefully and prints information on errors instead of crashing when encountering errors while writing data to the destination table.
Fixed handling of oversized messages exchanged between kudu-master process and Ranger client. This fixes fine-grained authorization issues when working with a cluster having thousands of tables (see KUDU-3450 and KUDU-3489).
Fixed at-rest encryption/decryption when using OpenSSL 3.
Fixed incompatibility introduced with KUDU-2671 (see KUDU-3515).
Fixed master and tablet server crash when the system clock is synchronized by PTPd (see KUDU-3521).
Fixed NPE that might be thrown during RPC connection negotiation by Kudu Java client. The thrown exception would make the connection to the corresponding tablet server unusable, where the only remedy for the issue was a restart of the Kudu Java client application (see KUDU-3576).
Do not expose string gauges as Prometheus metrics (see KUDU-3549).
Fixed integer overflow in available space metrics (see KUDU-3562).
Don’t spam servers’ logs with “Entity is not relevant to Prometheus” (see KUDU-3561).
Fixed summary metrics in Prometheus format (see KUDU-3566).
Fixed a race condition that might lead to unexpected behavior when processing AlterTable or a scan request containing IN-list predicates with concurrently running major delta compaction (see KUDU-3569).
Fixed a heap-use-after-free bug in MajorDeltaCompactionOp. The bug might lead to unexpected behavior when processing an AlterTable request along with concurrently running major delta compaction (see KUDU-3570).
Fixed altering tables with custom per-range hash schemas (see KUDU-3577).
Disable KUDU-3367 behavior by default. This fixes major delta compaction failure that manifests itself in certain workloads with copious number of DELETE operations (see KUDU-3619).
Fixed Impala daemon crash caused due to improper handling of a no-longer-existing tablet (see KUDU-3461).
The Kudu CLI’s can now accommodate response payloads up to 2GByte in size with the increased maximum RPC message size limit.
Fixed incorrect memory budgeting condition in compaction that could cause budgeting logic to not kick in when required.
Fixed Ranger client issue to avoid spawning of Ranger subprocess if keytab file is not available (see KUDU-3558).
Fixed a bug where the Ranger client could silently crash leaving the Kudu masters running, but not being able to serve requests (see KUDU-3504).
Fixed a bug that the table could stay in ALTERING state forever if its replication factor changes when it does not have any tablets.
Fixed a bug in Kudu Java client that might lead to a Scanner not found exception (see KUDU-3526).
Fixed a bug where the result of UPSERT might not be correct when the client schema and server schema do not match (see KUDU-3495).
Fixed a bug where the log cache of the tombstoned tablet might not be cleared (see KUDU-3535).
Fixed a bug where the maintenance manager might schedule fewer operations even if there are idle threads and pending operations. (see KUDU-3516).
Fixed a bug when a new master with empty local directories tries to connect to an existing cluster (see KUDU-3437).
Fixed a bug in multi-master cluster with non-default Kerberos principal name.
Fixed a bug in multi-master cluster when MiniDumps enabled (see KUDU-3491).
Content-Type headers have been corrected for various HTTP/HTTPS endpoints, ensuring accurate response formats, including support for JSON and binary data where applicable (see KUDU-3543).
SSE2 and AVX code now uses native NEON instructions on ARM64/AArch64 (see KUDU-3475).
Fixed IN list predicate pruning for tables with range specific hash schema (see KUDU-3564).
Kudu Java client now properly handles concurrent table schema updates between consecutive write operations within the same KuduSession (see KUDU-3483).
Fixed heap-use-after-free issue in OpDriver (see KUDU-3620).
Fixed handling of unexpected input for --predicates flag in kudu table scan and other CLI tools,
so the tools wouldn’t crash on incorrect user input, but report on problems with actionable error
messages. For details, see KUDU-3623.
Fixed zlib-related errors when processing HMS notification events (see KUDU-3648.
Fixed the issue where DnsResolver threads were not shutdown causing retrying of RPCs that failed due to server shutdown process (see KUDU-3633).
Fixed crash of Kudu CLI tool namely kudu table copy in cases of invalid inputs (see KUDU-3623).
== Wire Protocol compatibility
Kudu 1.18.0 is wire-compatible with previous versions of Kudu:
Kudu 1.18 clients may connect to servers running Kudu 1.0 or later. If the client uses features that are not available on the target server, an error will be returned.
Rolling upgrade between Kudu 1.17 and Kudu 1.18 servers is believed to be possible though has not been sufficiently tested. Users are encouraged to shut down all nodes in the cluster, upgrade the software, and then restart the daemons on the new version.
Kudu 1.0 clients may connect to servers running Kudu 1.18 with the exception of the below-mentioned restrictions regarding secure clusters.
The authentication features introduced in Kudu 1.3 place the following limitations on wire compatibility between Kudu 1.18 and versions earlier than 1.3:
If a Kudu 1.18 cluster is configured with authentication or encryption set to "required", clients older than Kudu 1.3 will be unable to connect.
If a Kudu 1.18 cluster is configured with authentication and encryption set to "optional" or "disabled", older clients will still be able to connect.
The Kudu 1.18 Java client library is API- and ABI-compatible with Kudu 1.17. Applications written against Kudu 1.17 will compile and run against the Kudu 1.18 client library and vice-versa. NOTE: As part of the Gradle upgrade to version 7.6.4, additional runtime dependencies have been introduced in the published artifacts. These dependencies were optional in earlier versions and, therefore, were not included in the corresponding POM files of those artifacts.
The Kudu 1.18 C++ client is API- and ABI-forward-compatible with Kudu 1.17. Applications written and compiled against the Kudu 1.17 client library will run without modification against the Kudu 1.18 client library. Applications written and compiled against the Kudu 1.18 client library will run without modification against the Kudu 1.17 client library.
The Kudu 1.18 Python client is API-compatible with Kudu 1.17, as no breaking changes have been introduced. However, support for Python versions 3.0 through 3.5 (inclusive) has been dropped. Users on these versions should upgrade to a supported Python version. Applications written against Kudu 1.17 will continue to work with the Kudu 1.18 client, and vice versa, as long as a supported Python version is used.
The Kudu CLI tool sometimes crashes on exit with SIGSEGV in OPENSSL_cleanup (see KUDU-3635).
Please refer to the Known Issues and Limitations section of the documentation.
Kudu 1.18.0 includes contributions from 26 people, including 3 first-time contributors:
halim.kim
qhsong
Sebastian Pop
Vladyslav Lyutenko
0xderek
For full installation details, see Kudu Installation.