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Forwarder Release Notes

The Forwarder is a central point of communication for an organization’s JVMs to reach Azul Intelligence Cloud. More information is available in One-time Setup for Azul Intelligence Cloud Within Your Organization.

Forwarder 2.0.0

Release date: May 19, 2026

Running hundreds or thousands of JVMs generates a large volume of events. Sending every event to Azul Intelligence Cloud is expensive in terms of network traffic, yet missing events means incomplete data and gaps in your analysis.

Forwarder 2.0.0 solves both problems at once. It introduces deduplication, which runs on your infrastructure before any data leaves your network. The Forwarder identifies duplicate events across JVMs within the same application environment and transmits only unique events to Azul Intelligence Cloud. You get complete, accurate data at a fraction of the transfer cost.

Note
This version of the Forwarder must be used in combination with the Azul Intelligence Cloud Agent 1.2.0 to be effective. For more information, see Agent 1.2.0 Release Notes.

What’s New

Event Deduplication: The forwarder now automatically filters duplicate events before forwarding them to Azul Intelligence Cloud. When multiple JVMs report the same classes, JARs, or methods, the forwarder detects duplicates and sends only unique events. This typically reduces network traffic between the forwarder and Intelligence Cloud by 85-95%.

Deduplication is enabled by default and requires no changes to your JVM agents.

Key Features

  • Two-layer caching: Fast in-memory cache for low-latency filtering, with an optional disk-based cache that preserves deduplication state across forwarder restarts.

  • Self-managing: The in-memory cache automatically manages memory under pressure. The disk-based cache auto-recovers from disk errors without manual intervention.

  • Deduplication monitoring: The health endpoint (/forwarder/health), status page, and Prometheus metrics now include deduplication statistics: saved bytes, dedup ratio, and cache health state.

  • Flexible deployment: Run with both caches (recommended), in-memory only (for stateless containers without disk), or as a passthrough proxy with deduplication disabled.

Updated Requirements

Component Previous (1.x) New (2.0) with deduplication

RAM

4 GB

8 GB

Disk

Not required

10 GB (SSD recommended)

CPU

1-2 cores

2 cores

-Xmx

1-2g

6g

Deduplication can be disabled (azul.deduplication.enabled=false) to retain the same resource requirements as Forwarder 1.x.

New Configuration Options

Setting (properties file) Description Default

azul.deduplication.enabled

Enable or disable deduplication

true

azul.deduplication.pipeline

ibf, lmdb (both caches) or ibf (in-memory only)

ibf, lmdb

azul.forwarder.fileCacheDirectory

Location for the disk-based cache

System temp dir

See Setting Up the Forwarder for more details.

Improvements

  • Prometheus metrics now include deduplication counters and ratios.

  • Health endpoint includes deduplication state in the overall health assessment.

  • Status page displays deduplication effectiveness (saved traffic, ratio).

Compatibility

  • Fully compatible with all existing Intelligence Cloud Agent versions

  • No agent-side configuration changes required

  • Upgrading from 1.x: update the forwarder JAR and increase memory/disk allocation per the updated requirements above

Forwarder 1.1.1

Release date: December 9, 2025

Improvements

  • Internal bugfixes and improvements.

Forwarder 1.0.9

Release date: October 27, 2025

Improvements

  • All Forwarder options and properties have been renamed to avoid collisions in configuration property names with other commonly used properties. See Setting Up the Forwarder for more details. Existing configuration files can still be used as the changes are backwards compatible.

  • The Forwarder now exposes multiple metrics in the Prometheus format, to integrate its statistics in, e.g. a Grafana dashboard, See Forwarder Metrics for more details.

Forwarder 1.0.8

Release date: April 28, 2025

Improvements

Forwarder 1.0.7

Release date: March 5, 2024

Improvements

  • All dependencies of the Forwarder are up-to-date and free of vulnerabilities as of the release date.

Bug Fix

  • Issue related to releasing runtime channels during artifact uploads to Intelligence Cloud. Previously, this led to the channel being closed unexpectedly, even if it was in use by another process at the time. This fix ensures that the connection/channel remains available for sharing and reuse as intended.

Forwarder 1.0.6

Release date: December 13, 2023

Improvements

  • All dependencies of the Forwarder are up-to-date and free of vulnerabilities as of the release date.

  • A custom header x-forwarder-time is added into every proxied request directed to Intelligence Cloud, serving as an indication of the time when the Forwarder proxies VM requests to Intelligence Cloud.

  • Network communication management between the Forwarder and the VM is improved. Robust network problem handling and comprehensive exchange of detailed information from the Forwarder to the VM has been implemented.

    The communication state logged on the VM side now contains this information:

     
    [CRS.connection][warning] Request postEventBatch failed on attempt 1 of 3, elapsed (4,361 ms): code= 502, message=Bad Gateway, payload=null, error=[Forwarder] The channel for uploading the artifact to Azul Intelligence Cloud has become inactive

    This contains more detailed information, compared to the log message in earlier versions of the Forwarder:

     
    [CRS.connection][warning] Request postEventBatch failed on attempt 1 of 3, elapsed (4,361 ms): java.net.SocketException: Unexpected end of file from server
  • The maximum length of the response content that Intelligence Cloud can send to the VM is increased from 64KB to 512KB. Additionally, you can configure the maximum size of response data that the Forwarder may forward to the Runtimes, thus minimizing potential impact.

    See for more details Forwarder Configuring Options.

Bug Fix

  • An issue is fixed where the system lacked the capability to effectively manage certificate-related issues arising from the expiration of the Forwarder certificate. In some cases, such as PC hibernation, the scheduled task of re-issuing the certificate was not executed, resulting in the VM rejecting the SSL handshake, despite the Forwarder functioning properly.

Forwarder 1.0.5

Release date: May 4, 2023

Improvements and Bug Fixes

Starting from version 1.0.5, you can configure the connection pool size to manage the number of simultaneous connections that are made from the Forwarder to Azul Intelligence Cloud. This allows you to optimize the system performance and minimize resource usage.

More details can be found in Forwarder Configuring Options.

Forwarder 1.0.4

Release date: March 14, 2023

Improvements and Bug Fixes

  • Fixed a performance issue with the connection pool used to connect to the cloud:

    The issue occurred when two or more threads attempted to establish a connection to the cloud simultaneously, with distinct index values. One thread was required to wait for the other, even though it was unnecessary, resulting in a delay. This unnecessary wait has been eliminated.

  • Resolved the problem resulting in a truncated response on the client side, which was caused by an incorrect value in the "Content-length" header when proxied by the Forwarder.

  • All dependencies of the Forwarder are up-to-date and free of vulnerabilities as of the release date.

  • Resolved an inconsistent state between the Forwarder state and the detailed metrics utilized for the computation of the state.

  • Enhanced the Forwarder’s functionality by adding comprehensive explanations in case the Forwarder state is not Green, enabling users to identify and address any issues with greater accuracy.

    See Status API for an example.

  • Resolved an issue concerning the retain/release of HTTP messages that were proxied by the Forwarder, which had the potential to result in memory leaks.

  • Implemented the feature to periodically monitor and store the status of the Forwarder to a file.

    See Forwarder Configuring Options for more information.

Forwarder 1.0.3

Release date: November 2, 2022

This version of the Forwarder contains several fixes and improvements in regards to the general launch of Azul Intelligence Cloud.

Improvements and Bug Fixes

  • Fixed issue with duplicate proxied requests.

  • Fixed IOException: Premature close → channelClosed on Forwarder.

    • A single HTTP/2 connection cannot be used due to load issues, HTTP/2 connection pool was introduced in order to be able to work under load.

    • Added the ability to calculate and log concurrent requests multiplexed into one HTTP/2 connection.

  • Improved error handling and permissions.

    • Enhanced readability of logged messages.

    • Allowed to optionally provide the HTTPS scheme for the IC host when starting the Forwarder.

Forwarder 1.0.2

Release date: October 18, 2022

Improvements and Bug Fixes

  • Minimise the number of Forwarder dependencies.

  • Added the ability to define the log level when starting the Forwarder using three different ways: via properties file, system variable or environment variable.

  • Fixed format of the Forwarder’s uptime. Added the ability to request extended statistics that include memory and CPU consumption.

  • Added homepage to the Forwarder when opening the root endpoint.

  • Simplification of the Forwarder authorization process.

  • Private key regeneration of the certificate on the Forwarder side during the daily certificate renewal process.

  • Added the ability to trust certificates issued to Azul by Amazon’s CA when the Forwarder connects to Azul Intelligence Cloud cloud.

  • No need to manually manage the certificates issued to the Forwarder.

Forwarder 1.0.1

Release date: October 4, 2022

Initial release (internal use only).