v2.7.3

NEW FEATURES

• add general.max_broken_part_ratio (env MAX_BROKEN_PART_RATIO, default 0) — when >0, create/create_remote skips broken data parts instead of aborting the whole backup as long as the broken/total part ratio stays at or below the configured fraction; skipped parts are logged as warnings and the backup is marked successful but partial; 0 preserves the legacy any-broken-part-fails behavior, fix #1418
• add clickhouse.rebind_replica_path_if_exists (env CLICKHOUSE_REBIND_REPLICA_PATH_IF_EXISTS, CLI --rebind-replica-path-if-exists, also accepted by the REST API POST /backup/restore endpoint) — opt-in rebind of the replicated table ZK path to default_replica_path during restore when the resolved path already has leftover children but no local table uses it (async-stale state after DROP); MUST stay false during a concurrent multi-replica restore to avoid split-brain, fix #849
• add gcs.disable_http2 (env GCS_DISABLE_HTTP2) — force HTTP/1.1 for the GCS client to avoid single-TCP-connection HTTP/2 multiplexing becoming the bottleneck for high-throughput parallel downloads, fix #1437

IMPROVEMENTS

• switch the S3 client retry mode from aws.RetryModeStandard to aws.RetryModeAdaptive, so upload/download retries back off with a client-side rate limiter under throttling (SlowDown/503) instead of a fixed token bucket
• support tables with ENGINE=Alias during restore — strip the explicit column list (Alias inherits columns from the target table) and add allow_experimental_alias_table_engine=1 for ClickHouse 25.11+, fix #1426
• skip tables from databases with engine DataLakeCatalog (read-only external catalogs) during backup, in addition to MySQL/PostgreSQL/MaterializedPostgreSQL, fix #1417
• speed up create on servers with many tables: batch the in-progress system.mutations lookup instead of issuing one query per table (O(N^2) -> O(N)), fix #1431
• speed up restore/download table list resolution: eliminate the O(N^2) linear duplicate scan in getTableListByPatternLocal/getTableListByPatternRemote via a shared O(1) dedup keyed on metadata.TableTitle, fix #1430
• extend TestFlows FIPS 140-3 test coverage: dedicated test steps, stronger --fips-info/version-output and TLS-handshake assertions, updated requirements documentation, fix #1443

BUG FIXES

• restore the default general.compression_use_multi_thread to true: #1378 defaulted it to false, which silently dropped gzip/zstd compression from multi-threaded (pre-1378 gzip always used pgzip) to single-threaded and caused ~30% slower upload throughput for backups dominated by one large table (where upload_concurrency provides no per-stream parallelism); the option is now silently ignored instead of failing config validation for formats other than gzip/zstd
• fix v2.7.1 regression where restore --schema on a second replica rebound the ZK replica path even while the first replica was active and healthy — a foreign/renamed local table occupying the resolved ZK path is still detected automatically via system.replicas and rebound to default_replica_path, but a non-empty ZK path without a local table now defaults to the HA-safe join and requires the new opt-in rebind_replica_path_if_exists, fix #1428
• fix inconsistent --rbac behavior: restore --rbac no longer returns an error when the backup contains no RBAC access directory, matching the download --rbac behavior, fix #1432
• inject ON CLUSTER for LIVE VIEW and WINDOW VIEW restored with explicit column lists when restore_schema_on_cluster is set — enrichQueryWithOnCluster missed these statements and the views were created only on the local replica, fix #1433
• mask sensitive values (passwords, storage credentials, encryption keys) when logging --env config overrides, and in the API server action logs and /backup/status output, fix #1441