2.6.42

v2.6.42

NEW FEATURES

• apply object disk key rewriting for remapped tables during restore to prevent data corruption when using --restore-database-mapping or --restore-table-mapping with object disks (S3/GCS/Azure), fix 1278
• add GCS customer-supplied encryption key (CSEK) support for client-side encryption where the encryption key is controlled by the user, not Google. Use GCS_ENCRYPTION_KEY environment variable or gcs.encryption_key config option with base64-encoded 256-bit key, fix 1316
• add TLS support for Keeper connections, allows secure connections to ClickHouse Keeper with SSL/TLS certificates, fix 1312
• add --skip-empty-tables option to restore and restore_remote commands to skip tables with no data during restore, available in CLI, API handlers, and server mode, fix 1265

IMPROVEMENTS

• implements batching keys deletions to improve speed of delete old backups during backup retention, fix 1066
• add ClickHouse 25.12 to test matrix
• add example for minimal grants for backup user in Examples.md
• improve GCS connection handling: properly close readers on error to prevent goroutine leaks, change retry logging from Debug to Warn level
• use partitionId directly instead of INSERT INTO temp table for ClickHouse 21.8+, improves partition handling performance, fix 1315
• refactor table column type checking to use single query before freeze operation instead of per-table queries fix 1194
• add KEEPER_TLS_ENABLES=1 by default in integration tests
• improve TestKeeperTLS, TestReplicatedCopyToDetached, and TestRestoreDistributedCluster test stability
• update GitHub Actions workflows and GOROOT configuration
• explain S3_FORCE_PATH_STYLE configuration option in documentation

BUG FIXES

• fix S3 multipart operations (upload, download, copy) to respect S3_MAX_PARTS_COUNT instead of hardcoded 10000 value, allows S3-compatible backends with stricter limits
• fix GCS credential conflicts when multiple authentication options are provided, refactor GCS Connect to avoid conflicting client options
• fix COS upload for large files, fix 1318
• fix list status update in server mode, fix 1317
• fix TestServerAPI and TestReplicatedCopyToDetached test failures in CI/CD
• fix OpenSSL/client config parsing for Keeper TLS connections, add comprehensive integration tests
• fix partition filtering when using --restore-database-mapping, --restore-table-mapping together with --partitions option
• security: update dependencies to fix CVE-2025-61729, CVE-2025-61727

2.6.41

v2.6.41

BUG FIXES

• improve restore long RBAC which have length more 64k, fix 1305

2.6.40

v2.6.40

IMPROVEMENTS

• add ClickHouse 25.10 and 25.11 support to CI/CD test matrix

BUG FIXES

• properly handle operationId in create_remote and restore_remote HTTP handlers, fix 1272
• improve --tables parameter to automatically adjust according to --restore-table-mapping logic, fix 1278, fix 1302
• fix Download and Upload command proper close resumable state to avoid infinite bolt lock in server mode when upload or download command failed, fix 1304
• fix ApplyMacros behavior for Embedded backup/restore
• fix config race conditions in server mode
• fix GCS transient errors causing corruption, fix 1292
• change GCS default chunk size to 16Mb, fix 1292
• fix support for object_disk.VersionFullObjectKey=5 in ClickHouse 25.10+, fix 1290
• fix restore refreshable materialized view, fix 1271

2.6.39

v2.6.39

BUG FIXES

• final improvements for check system.clusters during restore engine=Distributed and is not exists and if not macros use RESTORE_SCHEMA_ON_CLUSTER or CLICKHOUSE_RESTORE_DISTRIBUTED_CLUSTER config parameter as cluster value, fix 1252

2.6.38

v2.6.38

BUG FIXES

• check system.clusters during restore engine=Distributed and is not exists and if not macros use CLICKHOUSE_RESTORE_DISTRIBUTED_CLUSTER config parameter as cluster value, fix 1252

2.6.37

v2.6.37

BUG FIXES

• fix slowdown and corner cases, for incremental backup creation, affected 2.6.30+, fix #1249

2.6.36

v2.6.36

IMPROVEMENTS

• add GCS_SA_EMAIL option to support service account authorization, fix 1246 thanks @kamushadenes
• improve --hardlink-exists-files behavior, will look to exists local backups for the same part to avoid download unnecessary, fix 1244
• add S3_CHUNK_SIZE option to allow more flexible workload for S3-compatible remote storage, fix 1248 thanks @KimDoKy

2.6.35

v2.6.35

BUG FIXES

• fix corner case for restoring REFRESHABLE MATERIALIZED VIEWs, fix 1232
• fix errors during restore RBAC objects stored in old format, affected 2.6.34 fix 1238

2.6.34

v2.6.34

IMPROVEMENTS

• add full support for backup and restore of named collections, which can be stored in keeper or on the local filesystem. fix 961
• add --named-collections, --named-collections-only flag to create_remote and restore_remote commands.
• add named_collections_backup_always option to the general config section.
• add named collection size to the backup list output and API.
• add support for named collections parameters in API handlers.
• switch to Go 1.25.
• update default ClickHouse version to 25.8 and add it to the test matrix.

BUG FIXES

• fix restore schema on cluster for VIEW, fix 1199.
• disable free space check when using --hardlink-exists-files, fix 1198
• add chmod 0640 for --hardlink-exists-files during download and restore_remote, fix 1164

2.6.33

v2.6.33

BUG FIXES

• add creation integration tables for POST /restart and kill -SIGHUP reaction, fix 1195