v0.5.0

New Experiments

• New Pipeline class with new pipeline run logic - Pipeline example

Full Changelog: v0.4.0...v0.5.0

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🧬 New Pipeline Logic

This release introduces a reimplementation of the pipeline-run logic to resolve multiple issues, improving reliability and performance. These changes will also be included in Haystack 2.10.

Fixed Issues:

1. Exceptions in pipelines with two cycles

   • Pipelines with two cycles sharing an optional (like in PromptBuilder) or a greedy variadic edge (e.g., in BranchJoiner) might raise exceptions. Details here.

2. Incorrect execution in cycles with multiple optional or variadic edges

   • Entry points for cycles were non-deterministic, causing components to run with unexpected inputs or multiple times. This impacted execution time and final outputs.

3. Missing intermediate outputs in cycles

   • Outputs produced within a cycle were overwritten, preventing downstream components from receiving them.

4. Premature execution of lazy variadic components

   • Components like DocumentJoiner sometimes executed before receiving all inputs, leading to repeated partial executions that affected downstream results.

5. Order-sensitive behavior in add_component and connect

   • Some bugs above occurred due to specific orderings of add_component and connect in pipeline creation, causing non-deterministic behavior in cyclic pipelines.

Am I Affected by this Change?

• Non-cyclic pipelines without lazy variadic components:
  No impact—your pipelines should function as before.

• Non-cyclic pipelines with lazy variadic components:
  Check inputs and outputs of components like DocumentJoiner for issues #4 and #5. Use LoggingTracer with content tracing to validate behavior. Component execution order now uses lexicographical sorting; rename upstream components if necessary.

• Pipelines with cycles:
  Review your pipeline outputs as well as the component input and outputs to ensure expected behavior, as you may encounter any of the above issues.

Share your comments in discussion #177