Release notes for Instana agents

agent 1.1.778: Improves Linux hostname resolution by removing trailing newline characters from command output.

Previously, Linux hostname detection could include trailing newline characters from hostname command output, an issue introduced in Agent 1.2.66. Now, hostname and FQDN values are trimmed before being used.

• agent 1.1.777: Improved process output streaming reliability.
• agent-jvm-handling 1.0.48: Improved process output streaming reliability.
• agent-netty-allocator 1.0.5: Resolved memory corruption on OpenJ9 Java 17.
• agent-process-handling 1.0.50: Improved process output streaming reliability.
• agent-metaspace-monitor 1.0.1: Enhanced memory management.

• Previously, process output streaming could fail unexpectedly when the internal ThreadPool was prematurely cleaned up due to missing hard references. Now, session references are properly maintained throughout the process lifecycle, ensuring reliable output streaming for JVM attachment, Windows service monitoring, and support task execution.
• Previously, memory corruption crashes occurred in OpenJ9 Java 17 during direct buffer deallocation due to improper reallocation handling. Now, the capacity method properly uses reflection-based reallocation aligned with Netty's implementation, preventing memory corruption in stricter JVM environments.
• Previously, the metaspace monitor triggered agent reboots too aggressively at 20 MB threshold without attempting memory cleanup. Now, the threshold is relaxed to 15 MB and garbage collection is attempted before counting towards reboot triggers, reducing unnecessary restarts.

• sensor-api 1.2.182
• agent-json 1.2.182

• agent 1.1.776: Adds hostname resolution tracking and change detection.
• agent-task-orchestrator 1.0.11: Tracks thread pools and prevents task leaks.
• agent-jvm-handling 1.0.47: Standardizes JVM communication on AgentSocket endpoint.
• agent-metaspace-monitor 1.0.0: Monitors metaspace memory and triggers agent restart when threshold is reached.

All JVM-to-agent communication now uses the AgentSocket mechanism on port 42699, simplifying the communication architecture and improving reliability. The ENABLE_AGENT_SOCKET environment variable is now a no-op, and the legacy socket-based communication channel has been removed.

• Previously, ServiceLoader.load() failed in custom classloaders when loading services from META-INF/services. Now, both AgentInMemoryClassLoader and AgentURLClassloader properly support ServiceLoader discovery.
• Previously, non-root users could not attach to OpenJ9 JVMs when root created attachment lock files. Now, Byte Buddy 1.18.9 enforces 0666 permissions on lock files, enabling multi-user attachment.
• Previously, metaspace exhaustion could prevent the monitor from detecting low memory conditions. Now, the metaspace monitor runs as an independent bundle and triggers agent restart when less than 20 MB metaspace remains available, with faster detection (50 seconds vs 3 minutes).
• Previously, hostname changes went undetected, causing troubleshooting difficulties. Now, the agent tracks hostname resolution methods and detects changes with detailed diagnostics.
• Previously, unreferenced thread pools could leak tasks indefinitely. Now, the agent tracks all thread pools and automatically cancels tasks in unreferenced pools after 60 seconds.

• javaagent-loader 1.3.77
• attach-tools 1.18.9
• agent-task-orchestrator-api 1.0.5
• agent-util 1.0.22

• agent 1.1.775: Improves network interface detection.
• agent-jvm-handling 1.0.46: Resolves JVM connection stalls.
• agent-process-handling 1.0.49: Reduces logging verbosity.
• agent-sensor 1.0.5: Adds support for custom tags.
• agent-socket-server 1.0.14: Improves connection management reliability.

Custom tags that are configured in configuration.yaml are now reported to the backend, enabling better organization, and filtering of monitored entities.

You can now configure the network interface lookup interval through the INSTANA_NETWORK_LOOKUP_INTERVAL_SECONDS environment variable (minimum 10 seconds), which allows adjustment of network interface discovery frequency based on your environment needs.

Previously, JVM connections might stall when new connections replaced waiting connections, preventing proper instrumentation. Now, the agent closes the old waiting connections correctly to prevent stalls.

Previously, all network interfaces were returned regardless of status, potentially causing connectivity issues. Now, the agent includes only active (UP) network interfaces.

Previously, environment variables were logged in Process toString() output, creating excessive log noise. Now, the agent includes the environment variables only in toDebugString() methods with proper obfuscation.

• agent 1.1.774: Improved configuration file monitoring and JVM attachment diagnostics.
• agent-jvm-handling 1.0.45: Added monitoring issue for JVM attachment permission failures.
• javaagent-loader 1.3.76: Fixed loader startup on Java 1.6 with IBM WebSphere.

JVM attachment permission failures now generate a dedicated monitoring issue (jvm_attach_permission) for simplify diagnosis and troubleshooting.

• Previously, broken symbolic links in configuration directories caused continuous ERROR logs and prevented configuration files from being processed. Now, the agent skips broken symbolic links gracefully and continues configuration monitoring normally.
• Previously, the javaagent-loader failed to start on Java 1.6 with IBM WebSphere because of unhandled exceptions during MBean server initialization. Now, the loader handles all exceptions during MBean server preloading and continues startup successfully.

agent-util 1.0.21

• agent 1.1.773: Improved configuration file change detection.
• agent-jvm-handling 1.0.44: Added configurable JVM attachment logging.
• agent-process-handling 1.0.48: Extended IBM i process monitoring and improved container detection performance.

IBM i systems now detect native jobs in addition to PASE processes, enabling monitoring of IBM MQ and other native workloads.

JVM attachment operations can now log to stdout through the INSTANA_JVM_ATTACHMENT_LOG_TO_STDOUT environment variable, which improves troubleshooting in containerized environments.

Previously, configuration file changes in Kubernetes environments might be missed because of inotify limitations. Now, the agent combines event-based detection with polling to deduct configuration updates reliably.

Previously, Podman container ID detection used unnecessary processing in cgroupv2 environments, which increased CPU usage. Now, the agent skips this work in cgroupv2 environments to improve performance.

• agent-cgroup 1.0.12
• agent-runtime-api 1.0.18
• agent-runtime 1.0.22
• sensor-api 1.2.181
• agent-json 1.2.181
• netty 4.1.133.Final

• agent 1.1.772: Improved unique ID generation for Kubernetes environments, enhanced host ID handling for AWS Fargate, and fixed duplicate log file display on Windows.
• agent-backend 1.0.13: Added proactive monitoring to detect and recover from slow backend connections and stalled message queues.
• agent-jvm-handling 1.0.43: Re-enabled cleanup of stale attach files on z/OS systems.
• agent-process-handling 1.0.47: Fixed race condition in container process identification.

• OVN-Kubernetes interface filtering prevents MAC address collisions across clusters by excluding management port interfaces from unique ID generation.
• Automatic agent ID persistence activation when MAC addresses are unavailable, ensuring stable agent identification in dynamic environments.
• Backend connection health monitoring detects slow backends and stalled message queues, then automatically recovers to prevent memory exhaustion.
• DNS lookup optimization in Kubernetes environments reduces CoreDNS load and improves startup performance when the NODE_NAME environment variable is set.

• Previously, AWS Fargate task ARNs containing forward slashes caused log download failures with HTTP 400 errors. Now, the agent sanitizes host IDs to ensure URL compatibility.
• Previously, Windows systems displayed duplicate log files in the UI because path comparisons were not normalized. Now, the agent normalizes paths and compares case-insensitively on Windows.
• Previously, concurrent threads might overwrite valid container process IDs with null values. Now, proper synchronization prevents race conditions in container process identification.
• Previously, stale attach files accumulated on z/OS systems. Now, cleanup mechanisms properly remove stale temporary files.

• agent-netty42-pki 1.0.1
• agent-util 1.0.20

• javaagent-loader 1.3.75: Enhanced Elasticsearch compatibility and improved attach mechanism configuration.
• agent-jvm-handling 1.0.42: Improved cleanup operations, permission handling, and instana-sudo integration for JVM attachments.
• agent-process-handling 1.0.46: Enhanced z/OS support for WebSphere and Liberty selective monitoring.
• agent-windows-extensions 1.3.82: Enhanced IIS reset detection for .NET Full Framework monitoring.

• Added compatibility with the Elasticsearch entitlement system by using bytecode transformation, enabling the agent to attach without triggering security violations.
• Selective monitoring support for WebSphere and Liberty processes on z/OS platforms.
• Enhanced the attach mechanism for J9 and OpenJ9 JVMs. The agent now automatically adjusts the heap size to 128 MB when it uses JDK `tools.jar`.

• Previously, orphaned .dll and .so files from terminated processes accumulated in /tmp/.instana. Now, cleanup operations properly remove these files including libprofsensor libraries.
• Previously, J9 attach directory cleanup failed with an "Operation not permitted" error in non-root mode. Now, capability checks, such as CAP_FOWNER and CAP_DAC_OVERRIDE ensure cleanup only runs with appropriate permissions.
• Previously, IIS worker processes lacked visibility when CLR instrumentation required an iisreset. Now, the discovery-clr sensor reports when an IIS reset is needed and displays a clear message in the UI.

• agent 1.1.771: Added z/OS-specific persistence path for stable agent IDs across restarts.
• agent-configuration-integration-vault 1.0.19: Enhanced Key Vault V2 configuration validation with detailed logging for prefix-keypath combinations.

• Previously, z/OS agent generated a new unique ID on every restart in environments without standard network interface commands. This behavior might disrupt monitoring and cause loss of historical data continuity. The agent now persists the IDs to/var/instana/instana-agent-id and reused across restarts.
• Previously, incorrect Key Vault V2 prefix and key-path combinations causes wrong /data/ injection without clear indication. The agent now logs detailed information about configuration issues to help you identify and fix misconfigurations.

• agent 1.1.770
• agent-backend 1.0.12
• agent-cgroup 1.0.11
• agent-config-provider 1.0.2
• agent-configuration-integration-vault 1.0.18
• agent-cri-client 1.0.7
• agent-grpc 1.0.20
• agent-grpc-channel-cache 1.0.5
• agent-http 1.0.8
• agent-ibm-secrets-manager 1.0.3
• agent-ibmi-handler 1.0.4
• agent-internal-api 2.0.1
• agent-jvm-handling 1.0.41
• agent-open-telemetry-base 2.2.6
• agent-open-telemetry-grpc 1.1.18
• agent-open-telemetry-http 1.1.17
• agent-open-telemetry-http-api 1.0.7
• agent-open-telemetry-service 1.1.15
• agent-process-handling 1.0.45
• agent-prometheus 1.0.15
• agent-runtime 1.0.21
• agent-self-profiling 2.0.1
• agent-sensor 1.0.4
• agent-socket-server 1.0.13
• agent-socket-server-api 1.0.9
• agent-support-karaf 1.0.2
• agent-task-orchestrator 1.0.10
• agent-task-orchestrator-api 1.0.4
• agent-util 1.0.19
• commons-codec 1.21.0.instana-1
• commons-io 2.21.0.instana-1
• commons-lang3 3.20.0.instana-1
• discovery-ibmiseries 1.0.82
• discovery-power-hmc 1.0.22
• discovery-websphere 1.1.53
• jackson-annotations 2.21
• jackson-core 2.21.1
• jackson-databind 2.21.1
• jackson-dataformat-yaml 2.21.1
• jackson-datatype-jdk8 2.21.1
• netty-buffer 4.1.132.Final
• netty-codec 4.1.132.Final
• netty-codec-dns 4.1.132.Final
• netty-codec-http 4.1.132.Final
• netty-codec-http2 4.1.132.Final
• netty-codec-socks 4.1.132.Final
• netty-common 4.1.132.Final
• netty-handler 4.1.132.Final
• netty-handler-proxy 4.1.132.Final
• netty-resolver 4.1.132.Final
• netty-resolver-dns 4.1.132.Final
• netty-transport 4.1.132.Final
• netty-transport-native-unix-common 4.1.132.Final
• otel-sensorsdk-genai 1.0.4
• sensor-ibmiseries 1.0.82
• sensor-power-hmc 1.0.22
• sensor-websphere 1.1.53
• sensor-websphere-dmgr 1.1.53
• snakeyaml 2.6

• agent 1.1.769: Improved process lifecycle management on IBM i and z/OS platforms.
• agent-jvm-handling 1.0.40: Enhanced JVM discovery with configurable attach directories and non-root attachment support.
• agent-open-telemetry-grpc 1.1.17: Fixed TLS support for gRPC OTLP endpoint.
• agent-process-handling 1.0.44: Optimized container process matching and added retry mechanism for slow filesystems.
• agent-prometheus 1.0.14: Added snappy decoder support for Prometheus metrics.
• agent-socket-server 1.0.12: Fixed TLS support for gRPC OTLP endpoint.
• agent-windows-extensions 1.3.81: Improved InstanaPCP error handling for missing performance counters and invalid configuration.

• Configurable custom attach directories for JVM discovery to support non-standard temp directory locations.
• Snappy compression decoder support for Prometheus metrics.
• Monitoring event for missing HOME directory configuration issues.

• Previously, dead processes on IBM i and z/OS systems appeared alive with [cmdline_absent] marker. Now, proper SigarException is thrown for absent processes.
• Previously, gRPC OTLP endpoint (port 4317) did not support TLS connections. Now, TLS is properly configured and functional.
• Previously, container PID detection could fail on slow proc filesystems. Now, retry mechanism handles transient filesystem delays.
• Previously, InstanaPCP could exit when performance counters were missing or configuration was invalid. Now, InstanaPCP continues operating with appropriate error handling.

• agent-netty42-pki 1.0.0
• agent-permission 1.0.2
• agent-permission-api 1.0.1
• agent-runtime 1.0.20
• agent-runtime-api 1.0.17
• agent-socket-server-api 1.0.8

• agent 1.1.768: Fixed agent ID persistence path for containerized environments.
• agent-cgroup 1.0.10: Fixed cgroup parsing for cri-containerd environments.
• agent-process-handling 1.0.43: Improved container runtime compatibility with static linking and musl support.
• agent-self-profiling 2.0.0: Modernized profiling with Java Flight Recorder support.

• Self-profiling now uses Java Flight Recorder (JFR) instead of JVMTI, enabling profiling across HotSpot, OpenJDK, OpenJ9, and IBM Semeru JVMs without native dependencies.

• Previously, Podman container information was unavailable on older Linux distributions due to dynamic library dependencies. Now, static linking ensures compatibility across all Linux environments.
• Previously, cgroup file parsing failed with cri-containerd runtime due to extra colons in paths. Now, parsing correctly handles cri-containerd separator format.

Release date: 3 March 2026 | Version: 1.2.56 | Change Tag: 2026.03.03.2113

• agent-process-handling 1.0.42: Improved Windows compatibility and process argument handling.
• agent-jvm-handling 1.0.39: Enhanced socket communication reliability.

• Previously, the agent attempted to deploy the instana-sudo binary on Windows systems, causing permission errors. Now, the agent skips the deployment of the instana-sudo binary on Windows because Windows operations do not require it.
• Previously, socket connections between the agent and monitored JVMs might fail in environments with proxy configurations. Now, the agent bypasses proxy settings for direct JVM communication.
• Previously, on Windows systems with long process command lines exceeded 3,000 characters, the agent lost all process arguments due to UTF-16 truncation issues. Now, the agent sanitizes and preserves process arguments. It replaces invalid UTF-8 bytes with the replacement character (�).
• Previously, the agent might fail to retrieve container metadata in CRI-O environments, causing selective monitoring to malfunction. Now, the agent fetches the container metadata properly. Selective monitoring works correctly in CRI-O environments.

Release date: 2 March 2026 | Version: 1.2.55 | Change Tag: 2026.03.02.1407

• agent-permission 1.0.0: New permission-checking infrastructure with Linux capability detection for non-root operation.
• agent-permission-api 1.0.0: Permission checking API with composable predicates and detailed permission results.

• agent-jvm-handling 1.0.38: Integrated permission checks for JVM attachment operations.
• agent-process-handling 1.0.41: Integrated permission checks for container operations and added instana-sudo binary support.
• unix-socket-util 1.2.11: Added pre-flight permission checks before socket connections with caching.

• Non-root agent operation with comprehensive Linux capability detection and validation, including instana-sudo binary support for user change when needed.
• Permission checking system that detects required capabilities (CAP_DAC_OVERRIDE, CAP_DAC_READ_SEARCH, CAP_KILL, CAP_SETUID, CAP_SETGID, CAP_NET_ADMIN, CAP_NET_RAW, CAP_SYS_CHROOT, CAP_SYS_PTRACE, and CAP_SYS_ADMIN) for monitoring operations.
• Pre-flight Unix socket permission validation with 1-minute caching to prevent connection failures and provide early diagnostic feedback.

• agent-cgroup 1.0.9
• agent-process-handling-api 1.0.8
• agent-runtime 1.0.18
• agent-runtime-api 1.0.15
• agent-util 1.0.17

Release date: 26 February 2026 | Version: 1.2.54 | Change Tag: 2026.02.26.0814

• agent 1.1.767: Adds persistent agent ID functionality to maintain stable identification across restarts.
• agent-jvm-handling 1.0.37: Improves compatibility of IBM MQ monitoring with the OpenJ9 JVM.

Agent IDs can now persist across restarts when enabled by the INSTANA_PERSIST_HOST_UNIQUE_ID environment variable. This feature maintains a stable agent identity in dynamic environments like containers and virtual machines with changing network configurations.

Previously, monitoring IBM MQ processes on Windows caused continuous error pop-ups due to incompatible JVM attach attempts between HotSpot and OpenJ9. Now, the agent correctly uses MQ_JRE_PATH to attach correctly to IBM MQ processes with OpenJ9 JVM.

Release date: 24 February 2026 | Version: 1.2.53 | Change Tag: 2026.02.24.1336

• agent-open-telemetry-service 1.1.14: Improved OpenTelemetry metrics processing performance.
• agent-jvm-handling 1.0.36: Fixed cleanup of stale attachment files.

• Previously, OpenTelemetry metrics processing triggered repeated DNS queries for hostname resolution. This behavior caused performance degradation and potential failures in restricted network environments. Now, hostname resolution uses a cached value, which eliminates redundant DNS queries and improves reliability.
• Previously, stale .attach_pid files that are accumulated in application working directories when target JVM processes terminated during agent attachment. Now, attachment file cleanup works correctly even when processes terminate unexpectedly, which prevents file accumulation.

Release date: 16 February 2026 | Version: 1.2.52 | Change Tag: 2026.02.16.0626

agent-socket-server 1.0.11: Resolved an agent startup hang caused by entropy starvation.

Previously, the agent might hang during startup while generating self-signed certificates due to entropy starvation. Now, the agent uses a nonblocking SecureRandom implementation to prevent startup delays.

Release date: 12 February 2026 | Version: 1.2.51 | Change Tag: 2026.02.12.0856

• agent-cgroup 1.0.8: Enhanced support data collection with comprehensive cgroup file tracking and diagnostic information.
• agent-jvm-handling 1.0.35: Added unique memory markers to identify and filter internal JVM version check processes.
• agent-sensor 1.0.3: Fixed a blocking issue in sensor data collection by improving asynchronous reset handling.
• agent-socket-server 1.0.10: Added automatic generation of self-signed certificates for TLS endpoints.

• Cgroup support data now includes process-to-cgroup mappings, file presence manifests, raw file contents, and parsed statistics for CPU, Memory, and Block I/O (blkio) subsystems across both cgroup v1 and v2. This data provides detailed diagnostic information for troubleshooting container resource management.
• TLS endpoints automatically generate self-signed certificates when user certificates are unavailable. This behavior prevents plaintext responses and ensures secure connections.

• Previously, cgroup v2 memory parsing incorrectly included kernel memory in userspace calculations, and total memory did not include all components for out-of-memory (OOM) evaluation. Now, userspace memory reflects application memory usage. All memory components are exposed correctly, and total memory correctly includes all memory used to evaluate cgroup OOM conditions.
• Previously, agent sensor reset operations blocked data collection. Now, reset run asynchronously, which ensures the agent sensor can always provide data without interruption.
• Previously, agent's internal JVM version check processes appeared as "Unknown" entities in monitoring. Now, the agent uses unique memory markers (-Xms15728640 and -Xmx15728640) to identify and automatically filter these processes.

• agent 1.1.766
• agent-backend 1.0.11
• agent-config-provider 1.0.1
• agent-internal-api 2.0.0
• agent-memory 1.0.2
• agent-open-telemetry-grpc 1.1.16
• agent-open-telemetry-http 1.1.16
• agent-process-handling 1.0.40
• agent-process-handling-api 1.0.7
• agent-self-profiling 1.0.2
• agent-socket-server-api 1.0.7
• agent-task-orchestrator 1.0.9
• agent-task-orchestrator-api 1.0.3
• sensor-api 1.2.180
• agent-json 1.2.180

• agent-jvm-handling 1.3.73: Added Java 26 support and improved process discovery for z/OS Liberty.
• agent-process-handling 1.0.39: Improved selective monitoring with parent process inheritance.

• Java 26 support through updated instrumentation-shared (1.0.148) and instrumentation-boot (1.1.33) dependencies, enabling monitoring of applications that run on the latest Java version.
• Process discovery for WebSphere Liberty in CICS regions on z/OS for improved mainframe visibility.
• Parent process inheritance for selective monitoring in OPT_IN and OPT_OUT modes ensures consistent behavior across process hierarchies.

• Fixed inconsistent plug-in configuration order to ensure predictable behavior.
• JVM discovery now runs asynchronously in background threads, preventing agent startup blocking.

• agent-jvm-handling 1.0.33: Improved JVM version detection and attachment logic.
• agent-netty-allocator 1.0.4: Improved memory management for Netty channels.
• agent-process-handling 1.0.38: Improved process monitoring and handling of Windows performance counter.

JVM versions earlier than 1.6 are automatically excluded from monitoring, improving agent startup performance.

• Fixed InstanaPCP crashes on non-English Windows systems by correctly calculating buffer size for translated performance counter names.
• Fixed incorrect monitoring of container processes with empty command lines; agent now correctly identifies successful reads and creates processes to monitor only when appropriate.
• Fixed potential memory leaks by implementing WeakReference for Netty channel cleanup.

• agent-jvm-handling 1.0.32: Improves handling of ignored Java processes and JVM attachment.
• agent-ibmi-handler 1.0.3: Adds an API to access AS400 objects from connections.
• agent 1.1.764: Enhances log file discovery for custom log paths.

• Agent UI discovers and displays logs from custom paths that are configured in org.ops4j.pax.logging.cfg for improved visibility into application logs that are stored in nonstandard locations.
• IBM i sensor can access AS400 objects directly from AS400Connection instances for more efficient integration with IBM i systems.

• Fixed incorrect deletion of hsperfdata files for ignored Java processes; agent now stops monitoring without deleting attach files.
• Fixed misidentification of transitioning processes as JVMs that caused SIGQUIT signals to non-Java processes. Configure INSTANA_JVM_HANDLING_REQUIRE_ATTACH_FILES=true to attach only to JVMs with valid attach files (disabled by default).
• Updated Netty from 4.1.125.Final to 4.1.129.Final to address security vulnerability CVE-2025-67735.

• agent-open-telemetry-grpc 1.1.15: Adds support for a configurable legacy OTLP gRPC port.
• javaagent-loader 1.3.72: Prevents class loading errors during agent upgrades.
• agent-jvm-handling 1.0.31: Improves JVM attachment compatibility.
• agent-process-handling 1.0.36: Enhances process monitoring stability and secret masking.

• Configurable legacy OTLP gRPC port (55680) through INSTANA_AGENT_OTEL_GRPC_LEGACY_PORT_ENABLED environment variable or configuration file. Operators control port usage based on deployment needs.
  • Default value: true for agent versions earlier than 1.310.0
  • Default value: false for agent versions 1.310.0 and later

• As an alternative, you can also enable the legacy port in the configuration.yaml at com.instana.plugin.opentelemetry -> grpc -> legacy_port_enabled.

For more information, see Legacy OTLP gRPC port.

• Fixed process start time changes during agent restarts that triggered false service alerts; start times now remain stable during agent updates and restarts.
• Fixed NoClassDefFoundError failures when javaagent-loader JAR is deleted at runtime by pinning loader classes at startup.
• Fixed incorrect exclusion of JVMs with custom class loaders (example, WebLogic's LaunchClassLoader); the agent now excludes only unsupported SAS custom class loaders.
• Fixed exposure of secrets in Containerd container environment variables when using CRI client; agent now correctly masks secrets in all container configuration locations.