What’s New in Redpanda
This topic includes new content added in version 25.3. For a complete list of all product updates, see the Redpanda release notes. See also:
| Redpanda v25.3 introduces breaking schema changes for Iceberg topics. If you are using Iceberg topics and want to retain the data in the corresponding Iceberg tables, review Schema Changes and Migration Guide for Iceberg Topics in Redpanda v25.3 before upgrading your cluster, and follow the required migration steps to avoid sending new records to a dead-letter queue table. |
Iceberg topics with GCP BigLake
A new REST catalog integration with Google Cloud BigLake allows you to add Redpanda topics as Iceberg tables in your data lakehouse.
See Use Iceberg Catalogs for details on configuring Iceberg REST catalog integrations with Redpanda.
Shadowing
Redpanda v25.3 introduces Shadowing, an enterprise-licensed disaster recovery solution that provides asynchronous, offset-preserving replication between distinct Redpanda clusters. Shadowing enables cross-region data protection by replicating topic data, configurations, consumer group offsets, ACLs, and Schema Registry data with byte-level fidelity.
The shadow cluster operates in read-only mode while continuously receiving updates from the source cluster. During a disaster, you can failover individual topics or an entire shadow link to make resources fully writable for production traffic. See Failover Runbook for emergency procedures.
Shadowing includes comprehensive metrics for monitoring replication health. See Monitor Shadowing and Shadow Link metrics reference.
Connected client monitoring
You can view details about Kafka client connections using rpk or the Admin API ListKafkaConnections endpoint. This allows you to view detailed information about active client connections on a cluster, and identify and troubleshoot problematic clients. For more information, see the connected client details example in the Manage Throughput guide.
New Admin API style
Redpanda v25.3 introduces a new API style for the Admin API, powered by ConnectRPC. New Redpanda features and operations in v25.3 are available as ConnectRPC services, allowing you to use autogenerated Protobuf clients in addition to using HTTP clients such as curl.
Use the new ConnectRPC endpoints with the following v25.3 features:
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Shadowing
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Connected client monitoring
Existing Admin API endpoints from versions earlier than 25.3 remain supported, and you can continue to use them as usual. See Manage Redpanda with the Admin API to learn more about Admin API, and the Admin API reference to view the new endpoints.
Schema Registry import mode
Redpanda Schema Registry now supports an import mode that allows you to import existing schemas and retain their current IDs and version numbers. Import mode is useful when migrating from another schema registry.
Starting with this release, import mode must be used when importing schemas. Read-write mode no longer allows specifying a schema ID and version when registering a schema. See Use the Schema Registry API.
Security report
You can now generate a security report for your Redpanda cluster using the /v1/security/report Admin API endpoint. The report provides detailed information about TLS configuration, authentication methods, authorization status, and security alerts across all Redpanda interfaces (Kafka, RPC, Admin, Schema Registry, HTTP Proxy).
Topic identifiers
Redpanda v25.3 implements topic identifiers using 16 byte UUIDs as proposed in KIP-516.
Shadowing metrics
Redpanda v25.3 introduces comprehensive Shadowing metrics for monitoring disaster recovery replication:
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redpanda_shadow_link_client_errors- Track Kafka client errors during shadow link operations -
redpanda_shadow_link_shadow_lag- Monitor replication lag between source and shadow partitions -
redpanda_shadow_link_shadow_topic_state- Track shadow topic state distribution across links -
redpanda_shadow_link_total_bytes_fetched- Monitor data transfer volume from source cluster -
redpanda_shadow_link_total_bytes_written- Track data written to shadow cluster -
redpanda_shadow_link_total_records_fetched- Monitor total records fetched from source cluster -
redpanda_shadow_link_total_records_written- Track total messages written to shadow cluster
For monitoring guidance and alert recommendations, see Monitor Shadowing.
New commands
Redpanda v25.3 introduces the following rpk shadow commands for managing Redpanda shadow links:
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rpk shadow config generate- Generate configuration files for shadow links -
rpk shadow create- Create new shadow links -
rpk shadow update- Update existing shadow link configurations -
rpk shadow list- List all shadow links -
rpk shadow describe- View shadow link configuration details -
rpk shadow status- Monitor shadow link replication status -
rpk shadow failover- Perform emergency failover operations -
rpk shadow delete- Delete shadow links
In addition, the following commands have been added:
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rpk cluster connections- Monitor cluster connections and client statistics. -
rpk redpanda config print- Display node configuration.
New configuration properties
Redpanda 25.3 introduces the following configuration properties:
Shadowing:
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enable_shadow_linking: Enable shadow links (Enterprise license required)
Timestamp validation:
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log_message_timestamp_after_max_ms: Maximum timestamp difference for future records -
log_message_timestamp_before_max_ms: Maximum timestamp difference for past records -
message.timestamp.after.max.ms: Topic-level timestamp validation (future) -
message.timestamp.before.max.ms: Topic-level timestamp validation (past)
Audit logging:
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audit_use_rpc: Use internal RPCs for audit logging
Object storage:
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cloud_storage_client_lease_timeout_ms: Object storage connection timeout -
cloud_storage_gc_max_segments_per_run: Limits segment deletion rate during object storage housekeeping
Iceberg:
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iceberg_default_catalog_namespace: Default Iceberg catalog namespace for tables -
iceberg_dlq_table_suffix: Iceberg DLQ table name suffix -
iceberg_rest_catalog_gcp_user_project: GCP project for Iceberg REST catalog billing -
iceberg_topic_name_dot_replacement: Dot replacement in Iceberg table names
TLS:
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tls_v1_2_cipher_suites: TLS 1.2 cipher suites for client connections -
tls_v1_3_cipher_suites: TLS 1.3 cipher suites for client connections
Tiered Storage:
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cloud_topics_epoch_service_epoch_increment_interval: Cluster epoch increment interval -
cloud_topics_epoch_service_local_epoch_cache_duration: Local epoch cache duration -
cloud_topics_short_term_gc_backoff_interval: Short-term garbage collection backoff interval -
cloud_topics_short_term_gc_interval: Short-term garbage collection interval -
cloud_topics_short_term_gc_minimum_object_age: Minimum object age for garbage collection
Other configuration:
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controller_backend_reconciliation_concurrency: Maximum concurrent controller reconciliation operations -
fetch_max_read_concurrency: Maximum concurrent partition reads per fetch request -
kafka_max_message_size_upper_limit_bytes: Maximum allowedmax.message.sizetopic property value -
kafka_produce_batch_validation: Validation level for produced batches -
log_compaction_max_priority_wait_ms: Maximum time a priority partition can wait for compaction before preempting regular compaction -
log_compaction_tx_batch_removal_enabled: Enable transactional batch removal during compaction -
sasl_mechanisms_overrides: SASL authentication mechanisms per listener
Changes to default values
The following configuration properties have new default values in v25.3:
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core_balancing_continuous: Changed fromfalsetotrue(Enterprise license required). -
partition_autobalancing_mode: Changed fromnode_addtocontinuous(Enterprise license required). -
iceberg_throttle_backlog_size_ratio: Changed from0.3tonull.
Behavior changes
The following topic properties now support enhanced tristate behavior:
Previously, these properties treated zero and negative values the same way. Now they support three distinct states: positive values set specific limits, zero provides immediate eligibility for cleanup/compaction, and negative values disable the feature entirely. Review your topic configurations if you currently use zero values for these properties.
Deprecations
The following configuration properties have been deprecated in v25.3 and will be removed in a future release:
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kafka_memory_batch_size_estimate_for_fetch: No replacement. Remove from configuration. -
log_compaction_disable_tx_batch_removal: Uselog_compaction_tx_batch_removal_enabledinstead. Note the inverted logic: the new property enables the behavior when set totrue. -
log_message_timestamp_alert_after_ms: Uselog_message_timestamp_after_max_msinstead. -
log_message_timestamp_alert_before_ms: Uselog_message_timestamp_before_max_msinstead. -
raft_recovery_default_read_size: No replacement. Remove from configuration.
Deprecated features
Redpanda has deprecated support for specific TLSv1.2 and TLSv1.3 cipher suites and now uses more secure defaults. See Deprecated Features for the complete list.
