CHANGELOG.md

Changelog

All notable changes to this project will be documented in this file.

The format is based on Keep a Changelog, and this project adheres to Semantic Versioning.

[Unreleased]

Changed

• logrotate_fs is now behind a feature flag and not enabled in the default build. It remains enabled in the release artifact.
• The build now includes http1 and http2 support. Actual usage and availability may vary.

[0.24.0]

Added

• Introduced load profile configuration for logrotate FS. This is a breaking configuration change.

[0.23.5]

Fixed

• Target pid watcher will not report 0 for containers.

Removed

• Container is now the only supported release artifact, removing crates.io publish and binaries.

[0.23.4]

Added

• Introduced logrotate_fs, a sub-generator of file_gen that exposes a FUSE filesystem to mimic log rotation. Accurately records bytes lost by readers via rotation.

Fixed

• The target metrics prometheus parser now handles labels that have spaces in them rather than incorrectly identifying the metric value.
• Prometheus target metrics scraper will no longer panic if a metric has an invalid value (instead it will be logged)
• HTTP traffic sent by the HTTP generator and Splunk generator now always includes a Host header to comply with HTTP 1.1 requirements

[0.23.3]

Changed

• Linux observer is more resilient to scenarios where lading lacks ptrace permission.

Removed

• lading_capture no longer exports a protobuf version of the capture.

Added

• HTTP blackhole now has a response_delay_millis setting, allowing for simulation of latent network connections. The default value is 0.

Fixed

• Logrotate file generator will no longer panic when rotating files beyond one depth.

[0.23.2]

Changed

• Now built using rust 1.81.0.

Fixed

• Warmup period is now respected when container targeting is in use.
• Capture manager waits for the target to start running before recording data.

[0.23.1]

Fixed

• Fixes a panic in the signal mechanism that appeared when using the file generator most prominately.

[0.23.0]

Added

• Added ability to create tags for both expvar and prometheus target metrics specific to a single target_metrics configuration (example below shows prometheus metrics collected from the core agent and two additional tags created)

  target_metrics:
    - prometheus: #core agent telemetry
        uri: "http://127.0.0.1:5000/telemetry"
        tags:
          sub_agent: "core"
          any_label: "any-string-value"

[0.22.0]

Fixed

• Fixes bugs in smaps parsing code that can result in under-counting RSS in the smaps view of the data.
• Target observer was not exposed through CLI.

Changed

• Now built using rust 1.79.0

Added

• Target observer now allows a docker target, identified by name.
• Lading experiment duration may be set to (effectively) infinite via --experiment-duration-infinite.
• Allow lading to export prometheus over UDS socket.

[0.21.1]

Changed

• Added lading version to initial welcome print msg.

Fixed

• Prometheus metric exporter did not include some internal metrics (generator metrics)
• Range values in the dogstatsd payload will now generate the full inclusive range. Previously, values were generated up to but not including the max value.
• HTTP Blackhole now supports ZSTD encoded requests

[0.21.0]

Changed

• Improved the block cache construction to better fill the pre-defined space.
• Removed streaming cache method. Fixed is now the only option.
• Users now configure a maximum block size in generators, not individual blocks.
• Maximum datagram size in bytes for unix datagram generator is 8,192.
• Altered default cache construction from 'fixed' to 'streaming'
• Increased maximum DogStatsD context limit from 100k to 1M
• Procfs generator now generates process names as long as 254 characters, up from 253.

Fixed

• The capture manager will no longer panic if recording a capture and checking for a shutdown combined takes longer than one second.
• A shutdown race was partially fixed in the capture manager which could result in truncated (invalid) json capture files.
• Unix datagram generator will not longer 'shear' blocks across datagrams.
• Procfs generator now generates pid/stat files with comm in parens, matching Linux behavior.

[0.20.10]

Added

• Optional new feature for DogStatsD generation -- metric name prefixing.
• Musl builds are now available for aarch64 and x86-64

Changed

Fixed

[0.20.9]

Added

• Enforces changelog entries via CI check
• payloadtool binary useful for developers writing new experiments.
• Respects the env var RUST_LOG to control logging.

Fixed

• During payload generation, blocks will reliably be filled to the requested amount.
• During payload generation, block chunks now give more feedback when the requested amount cannot be hit.
• Does not crash on empty line in prometheus exports

Changed

• Increases the amount of blocks available during payload generation.
• DogStatsD tag generation updated to better reflect real DSD traffic.
• Users should avoid setting custom block_sizes and rely on the default blocks. payloadtool is available to help evaluate block size options.

[0.20.8]

Added

• Parse working set memory from cgroups on Linux, opens the door to future cgroups inspection.

[0.20.7]

Fixed

• Fix panic in memory map reading code

[0.20.6]

Added

• Adds /proc/<pid>/smap parsing to add very detailed memory usage.

Fixed

• Fixed a bug in CLI key/value parsing where values might be incorrectly parsed as key/value pairs if they held lading's delimiter character.

[0.20.5]

Added

• Adds a new config option to lading_payload::dogstatsd::Config, length_prefix_framed. If this option is on, each "block" emitted by the dogstatsd generator will have a little-endian u32 prefix (4 bytes) containing the length of the following block.

Fixed

• Total CPU calculation routine no longer panics in some scenarios
• Fixes bug with retry logic in both unix-stream and tcp generators that could result in unexpected, extra connections.

[0.20.4]

Added

• lading.running gauge metric that submits a value of 1 as long as the main select! of lading is executing.
• target.running gauge metric that submits a value of 1 as long as the target is running.

Changed

• Dogstatsd payload structs now have public fields.
• Capture file descriptor is flushed as soon as current lines are written.
• Renamed Shutdown data type to Phase so that this data type can be used as a signal to control lading behavior over distinct stages of load generation (e.g., warmup, shutdown).
• Prometheus telemetry and Go expvar target metrics are no longer emitted during lading's warmup ("experimental") phase.

Fixed

• Refactors the main select! in lading/src/bin/lading.rs to loop over the select to address a potential early-termination bug when the set of generators are empty.

[0.20.3]

Added

• ProcFs generator is now suitable for use.

[0.20.2]

Fixed

• Process gauges will now be zeroed before iteration. This prevents values from exited processes from being reported.

Changed

• Lading now aborts on panic.
• The shutdown mechanism has been adjusted to improve its reliability.
• The capture manager now runs on a background OS thread.

Added

• Added metrics that report CPU and memory usage of the whole target process tree.

[0.20.1]

Changed

• Internal shutdown sequence is now changed to an advisory signal. There is no user-facing change.
• Disabled ANSI codes in logging.

Fixed

• Removed generational storage in capture management, resolving a runtime hang.

[0.20.0]

Added

• Sampling and sampling probability configuration parameters added for dogstatsd payloads.
• A new 'logrotate' file generator is introduced.

Fixed

• Memory consumption stability issues in Dogstatsd payload generator

Changed

• Existing file generator is renamed 'traditional', requiring a configuration change.
• Unknown/old configuration keys are now rejected

[0.19.1]

Fixed

• Report scraped Prometheus counters correctly
• Correct metrics emitted by http blackhole

[0.19.0]

Changed

• HTTP blackhole can respond with arbitrary data.
• Dogstatsd payload generation now takes range configuration, allows constant settings.

[0.18.1]

Added

• lading-payload crate is now split out from the lading crate
• It is now possible for users to configure the range of DogStatsD payloads values. Previously the range was 64-bits wide. The range is inclusive or constant. Additionally, users may configure a probability for values being a floating point or not.

Changed

• The block mechanism is reworked to provide a 'fixed' and 'streaming' model, running in a separate OS thread from the tokio runtime.

[0.18.0]

Changed

• The predictive throttle no longer exists. The only options are stable and all-out.

[0.17.4]

Added

• lading and lading-capture releases are now published on crates.io.

[0.17.3]

Fixed

• We no longer incorrectly send multiple values on a SET metric in DogStatsD.

Changed

• Rust compiler updated to 1.71.0
• We now allow users to configure the number of multi-values in a DogStatsD metric.

[0.17.2]

Removed

• Observer no longer emits tick data for kernel and user-space time.

Changed

• We now avoid scaling utilization and clamp it directly to the appropriate range.
• We now elide sampling threads that are not also processes in the observer.
• Observer now distinguishes between parent and children processes.
• Config can now be specified using an env var LADING_CONFIG. If set, the env var takes precedence over the on-disk config file.
• We now expose two crates from this project, one for capture payloads and the other the main lading project.

[0.17.1]

Fixed

• Removed a leftover debug print in the Json payload implementation.

[0.17.0]

Changed

• Adjusted the default throttle to stable from predictive
• On Linux calculate CPU utilization in terms of logical, not physical, cores when possible.
• CPU percentage calculated in the same manner as Agent's
• Throttle metrics are now labeled with the respective generator's labels.
• Observer now calculates CPU utilization with respect to target cgroup hard, soft limits.

[0.16.1]

Changed

• Unix datagram connect errors are now logged at the error level.

Fixed

• No-target mode no longer hangs at startup
• The unix_datagram generator doesn't start generating data until the target is running.
• Panic fixed in unix_datagram generator

[0.16.0]

Added

• Generators and Blackholes now support an id configuration field. This will be added to all metrics produced by a component instance.

[0.15.3]

Changed

• Reduced the CPU time that file_gen consumes at the expense of slightly longer flush-to-disk times.
• file_gen now shares its pre-computed block between write children, reducing memory consumption.

[0.15.2]

Fixed

• Disallow the creation of DogStatsD metrics with no values

[0.15.1]

Added

• Add 'stable' throttle
• Add 'all-out' throttle
• Allow users to configure generators to use the various throttles
• Added the ability for users to configure DogStatsD payload kind ratios
• Added the ability for users to configure DogStatsd metric kind ratios

[0.15.0]

Added

• Added target metrics support for Go expvars
• Added target metrics support for Prometheus

Fixed

• Fixed throttle behavior for generators that run very quickly

[0.14.0]

Added

• Added the ability to configure details about DogStatsD payload

Changed

• Datadog logs generation now much faster, relying on an experimentally determined 'encoded size' rather than searching at runtime for the same. (PR #564).
• Adjust generators to consume less CPU by registering metrics where possible. (PR #544)
• Adjusted trace-agent msgpack payload generation to be much faster at the cost of some memory during the generation process. (PR #547)

[0.13.1]

Added

• Introduced Proportional Set Size (PSS) memory measurement under the pss_bytes metric.
• Convert Block to use Bytes type instead of Vec<u8>.
• Introduce Datadog trace-agent payload support in JSON and MsgPack serialization.

[0.13.0]

Added

• Introduced automatic throttling into generators to search for stable target load.

Fixed

• Use saturating addition in observer stats gathering routine

[0.12.0]

Added

• Added the ability for lading to back-off load generation based on RSS limits.
• Process tree generator contributed by @safchain
• Fixed: OpenTelemetry message length calculation corrected for some messages.
• Breaking change: Split UDS support between explict datagram and stream modules.
• Fixed: Corrected mistakes in the DogStatsD payload implementation.

Changed

• Adjusted the cardinality of DogStatsD keys, values and names downward.
• Breaking change: Added support for DogStatsD payload.
• Breaking change: Support for Kafka generator is removed.

Fixed

• Lading's UDS will now re-attempt to connect to a UDS socket, rather than erroring.

[0.11.3] - 2022-12-12

Fixed

• gRPC calls that respond with data are now handled correctly. This previously emitted an error and dropped the response.

[0.11.2] - 2022-12-01

Added

• Targets can inherit lading's environment variables using the --target-inherit-environment flag

Changed

• glibc based releases are now built on ubuntu-20.04 rather than ubuntu-latest

[0.11.1] - 2022-11-22

Added

• Releases now include x86-64 musl binaries
• The musl build does not support kafka

Changed

• The Protobuf compiler is no longer required to build lading

[0.11.0] - 2022-11-16

Added

• Observer now measures child processes of the target

[0.10.4] - 2022-11-16

Added

• HTTP blackhole can be configured with arbitrary response body, headers and status code
• gRPC HTTP2 client concurrency can now be configured

[0.10.3] - 2022-11-02

Fixed

• Works around an issue where the UDP generator would cause lading to never exit.

[0.10.2] - 2022-10-21

Fixed

• No notable code changes. Addresses issues with the release workflow.

[0.10.1] - 2022-10-20

Fixed

• No code changes. Addresses issues with the release workflow.

[0.10.0] - 2022-10-20

Added

• New payload: Apache Common
• New payload: OpenTelemetry protobufs for metrics, traces, and logs
• New generator: gRPC over HTTP/2
• Collect CPU, memory, and scheduling information about the target process
• Target processes may now be launched externally and watched by PID

Changed

• Breaking change: Support multiple generators and blackholes. These config sections are now lists.
• Breaking change: Share the same payload configuration across all generators. In alignment with other generators, the file generator now requires snake-cased payload names.
• HTTP and Splunk HEC blackholes support gzip decoding based on incoming headers
• TCP blackhole counts bytes recieved and publishes a bytes_received metric
• Ignore empty strings in CLI key-value arguments. This was previously an error.
• The static payload can accept a directory of files
• The file generator's file rotation behavior can be configured

Fixed

• Improve startup sequencing
• Fix TCP generator shutdown for long lived connections