docs: update README to include summarizer retry behavior and configuration details

Author: a-klos

libs/README.md

@@ -12,6 +12,7 @@ It consists of the following python packages:
   - [2.1 Requirements](#21-requirements)
   - [2.2 Endpoints](#22-endpoints)
   - [2.3 Replaceable parts](#23-replaceable-parts)
+  - [2.4 Summarizer retry behavior](#24-summarizer-retry-behavior)
 - [`3. Extractor API lib`](#3-extractor-api-lib)
   - [3.1 Requirements](#31-requirements)
   - [3.2 Endpoints](#32-endpoints)
@@ -71,6 +72,7 @@ By default `OpenAI` is used by the evaluation. If you want to use the same LLM-c
 Endpoint to remove documents from the vector database.
 
 #### `/information_pieces/upload`
+
 Endpoint to upload documents into the vector database. These documents need to have been parsed. For simplicity, a LangChain Documents like format is used.
 Uploaded documents are required to contain the following metadata:
 
@@ -94,7 +96,7 @@ Uploaded documents are required to contain the following metadata:
 | chat_graph | [`rag_core_api.graph.graph_base.GraphBase`](./rag-core-api/src/rag_core_api/graph/graph_base.py) | [`rag_core_api.impl.graph.chat_graph.DefaultChatGraph`](./rag-core-api/src/rag_core_api/impl/graph/chat_graph.py) | Langgraph graph that contains the entire logic for question answering. |
 | traced_chat_graph | [`rag_core_lib.chains.async_chain.AsyncChain[Any, Any]`](./rag-core-lib/src/rag_core_lib/chains/async_chain.py)| [`rag_core_lib.impl.tracers.langfuse_traced_chain.LangfuseTracedGraph`](./rag-core-lib/src/rag_core_lib/impl/tracers/langfuse_traced_chain.py) | Wraps around the *chat_graph* and add langfuse tracing. |
 | evaluator | [`rag_core_api.impl.evaluator.langfuse_ragas_evaluator.LangfuseRagasEvaluator`](./rag-core-api/src/rag_core_api/impl/evaluator/langfuse_ragas_evaluator.py) | [`rag_core_api.impl.evaluator.langfuse_ragas_evaluator.LangfuseRagasEvaluator`](./rag-core-api/src/rag_core_api/impl/evaluator/langfuse_ragas_evaluator.py) | The evaulator used in the evaluate endpoint. |
-| chat_endpoint | [ `rag_core_api.api_endpoints.chat.Chat`](./rag-core-api/src/rag_core_api/api_endpoints/chat.py) | [`rag_core_api.impl.api_endpoints.default_chat.DefaultChat`](./rag-core-api/src/rag_core_api/impl/api_endpoints/default_chat.py) | Implementation of the chat endpoint. Default implementation just calls the *traced_chat_graph* |
+| chat_endpoint | [`rag_core_api.api_endpoints.chat.Chat`](./rag-core-api/src/rag_core_api/api_endpoints/chat.py) | [`rag_core_api.impl.api_endpoints.default_chat.DefaultChat`](./rag-core-api/src/rag_core_api/impl/api_endpoints/default_chat.py) | Implementation of the chat endpoint. Default implementation just calls the *traced_chat_graph* |
 | ragas_llm | `langchain_core.language_models.chat_models.BaseChatModel` | `langchain_openai.ChatOpenAI` or `langchain_ollama.ChatOllama` | The LLM used for the ragas evaluation. |
 
 ## 2. Admin API Lib
@@ -115,7 +117,7 @@ The following endpoints are provided by the *admin-api-lib*:
 All required python libraries can be found in the [pyproject.toml](./admin-api-lib/pyproject.toml) file.
 In addition to python libraries, the following system packages are required:
 
-```
+```shell
 build-essential
 make
 ```
@@ -157,10 +159,10 @@ The extracted information will be summarized using LLM. The summary, as well as
 | key_value_store | [`admin_api_lib.impl.key_db.file_status_key_value_store.FileStatusKeyValueStore`](./admin-api-lib/src/admin_api_lib/impl/key_db/file_status_key_value_store.py) | [`admin_api_lib.impl.key_db.file_status_key_value_store.FileStatusKeyValueStore`](./admin-api-lib/src/admin_api_lib/impl/key_db/file_status_key_value_store.py) | Is used for storing the available sources and their current state. |
 | chunker |  [`admin_api_lib.chunker.chunker.Chunker`](./admin-api-lib/src/admin_api_lib/chunker/chunker.py) | [`admin_api_lib.impl.chunker.text_chunker.TextChunker`](./admin-api-lib/src/admin_api_lib/impl/chunker/text_chunker.py) | Used for splitting the documents in managable chunks. |
 | document_extractor | [`admin_api_lib.extractor_api_client.openapi_client.api.extractor_api.ExtractorApi`](./admin-api-lib/src/admin_api_lib/extractor_api_client/openapi_client/api/extractor_api.py) | [`admin_api_lib.extractor_api_client.openapi_client.api.extractor_api.ExtractorApi`](./admin-api-lib/src/admin_api_lib/extractor_api_client/openapi_client/api/extractor_api.py) | Needs to be replaced if adjustments to the `extractor-api` is made. |
-| rag_api | [`admin_api_lib.rag_backend_client.openapi_client.api.rag_api.RagApi`](./admin-api-lib/src/admin_api_lib/rag_backend_client/openapi_client/api/rag_api.py) | [`admin_api_lib.rag_backend_client.openapi_client.api.rag_api.RagApi`](./admin-api-lib/src/admin_api_lib/rag_backend_client/openapi_client/api/rag_api.py) | Needs to be replaced if changes to the `/information_pieces/remove` or `/information_pieces/upload` of the [`rag-core-api`](#rag-core-api) are made. |
+| rag_api | [`admin_api_lib.rag_backend_client.openapi_client.api.rag_api.RagApi`](./admin-api-lib/src/admin_api_lib/rag_backend_client/openapi_client/api/rag_api.py) | [`admin_api_lib.rag_backend_client.openapi_client.api.rag_api.RagApi`](./admin-api-lib/src/admin_api_lib/rag_backend_client/openapi_client/api/rag_api.py) | Needs to be replaced if changes to the `/information_pieces/remove` or `/information_pieces/upload` of the [`rag-core-api`](#1-rag-core-api) are made. |
 | summarizer_prompt | `str` | [`admin_api_lib.prompt_templates.summarize_prompt.SUMMARIZE_PROMPT`](./admin-api-lib/src/admin_api_lib/prompt_templates/summarize_prompt.py) | The prompt used of the summarization. |
 | langfuse_manager | [`rag_core_lib.impl.langfuse_manager.langfuse_manager.LangfuseManager`](./rag-core-lib/src/rag_core_lib/impl/langfuse_manager/langfuse_manager.py) | [`rag_core_lib.impl.langfuse_manager.langfuse_manager.LangfuseManager`](./rag-core-lib/src/rag_core_lib/impl/langfuse_manager/langfuse_manager.py) | Retrieves additional settings, as well as the prompt from langfuse if available. |
-| summarizer |  [`admin_api_lib.summarizer.summarizer.Summarizer`](./admin-api-lib/src/admin_api_lib/summarizer/summarizer.py) | [`admin_api_lib.impl.summarizer.langchain_summarizer.LangchainSummarizer`](./admin-api-lib/src/admin_api_lib/impl/summarizer/langchain_summarizer.py) | Creates the summaries. |
+| summarizer |  [`admin_api_lib.summarizer.summarizer.Summarizer`](./admin-api-lib/src/admin_api_lib/summarizer/summarizer.py) | [`admin_api_lib.impl.summarizer.langchain_summarizer.LangchainSummarizer`](./admin-api-lib/src/admin_api_lib/impl/summarizer/langchain_summarizer.py) | Creates the summaries. Uses the shared retry decorator with optional per-summarizer overrides (see 2.4). |
 | untraced_information_enhancer |[`admin_api_lib.information_enhancer.information_enhancer.InformationEnhancer`](./admin-api-lib/src/admin_api_lib/information_enhancer/information_enhancer.py) | [`admin_api_lib.impl.information_enhancer.general_enhancer.GeneralEnhancer`](./admin-api-lib/src/admin_api_lib/impl/information_enhancer/general_enhancer.py) |  Uses the *summarizer* to enhance the extracted documents. |
 | information_enhancer |  [`rag_core_lib.chains.async_chain.AsyncChain[Any, Any]`](./rag-core-lib/src/rag_core_lib/chains/async_chain.py)| [`rag_core_lib.impl.tracers.langfuse_traced_chain.LangfuseTracedGraph`](./rag-core-lib/src/rag_core_lib/impl/tracers/langfuse_traced_chain.py) |Wraps around the *untraced_information_enhancer* and adds langfuse tracing. |
 | document_deleter |[`admin_api_lib.api_endpoints.document_deleter.DocumentDeleter`](./admin-api-lib/src/admin_api_lib/api_endpoints/document_deleter.py) | [`admin_api_lib.impl.api_endpoints.default_document_deleter.DefaultDocumentDeleter`](./admin-api-lib/src/admin_api_lib/impl/api_endpoints/default_document_deleter.py) |  Handles deletion of sources. |
@@ -169,6 +171,33 @@ The extracted information will be summarized using LLM. The summary, as well as
 | document_reference_retriever | [`admin_api_lib.api_endpoints.document_reference_retriever.DocumentReferenceRetriever`](./admin-api-lib/src/admin_api_lib/api_endpoints/document_reference_retriever.py) | [`admin_api_lib.impl.api_endpoints.default_document_reference_retriever.DefaultDocumentReferenceRetriever`](./admin-api-lib/src/admin_api_lib/impl/api_endpoints/default_document_reference_retriever.py) | Handles return of files from connected storage. |
 | file_uploader | [`admin_api_lib.api_endpoints.file_uploader.FileUploader`](./admin-api-lib/src/admin_api_lib/api_endpoints/file_uploader.py) | [`admin_api_lib.impl.api_endpoints.default_file_uploader.DefaultFileUploader`](./admin-api-lib/src/admin_api_lib/impl/api_endpoints/default_file_uploader.py) | Handles upload and extraction of files. |
 
+### 2.4 Summarizer retry behavior
+
+The default summarizer implementation (`LangchainSummarizer`) now uses the shared retry decorator with exponential backoff from the core library.
+
+- Decorator: `rag_core_lib.impl.utils.retry_decorator.retry_with_backoff`
+- Base settings (fallback): [`RetryDecoratorSettings`](./rag-core-lib/src/rag_core_lib/impl/settings/retry_decorator_settings.py)
+- Per-summarizer overrides: [`SummarizerSettings`](./admin-api-lib/src/admin_api_lib/impl/settings/summarizer_settings.py)
+
+How it resolves settings
+
+- Each field in `SummarizerSettings` is optional. When a field is provided (not None), it overrides the corresponding value from `RetryDecoratorSettings`.
+- When a field is not provided (None), the summarizer falls back to the value from `RetryDecoratorSettings`.
+- Zero values (e.g., 0 or 0.0 where allowed) are honored and do not trigger fallback.
+- The effective retry configuration is computed once per summarizer instance at initialization.
+
+Configuring via environment variables
+
+- Summarizer-specific (prefix `SUMMARIZER_`):
+  - `SUMMARIZER_MAX_RETRIES`
+  - `SUMMARIZER_RETRY_BASE_DELAY`
+  - `SUMMARIZER_RETRY_MAX_DELAY`
+  - `SUMMARIZER_BACKOFF_FACTOR`
+  - `SUMMARIZER_ATTEMPT_CAP`
+  - `SUMMARIZER_JITTER_MIN`
+  - `SUMMARIZER_JITTER_MAX`
+- Global fallback (prefix `RETRY_DECORATOR_`): see section [4.2](#42-retry-decorator-exponential-backoff) for all keys and defaults.
+
 ## 3. Extractor API Lib
 
 The Extractor Library contains components that provide document parsing capabilities for various file formats and web sources. It supports extracting content from PDF, DOCX, XML files, as well as web pages via sitemaps and Confluence pages. It also includes a default `dependency_container`, that is pre-configured and is a good starting point for most use-cases. This API should not be exposed by ingress and only used for internally.
@@ -197,6 +226,7 @@ tesseract-ocr-eng
 ### 3.2 Endpoints
 
 #### `/extract_from_file`
+
 This endpoint will extract the information from PDF,PTTX,WORD,XML files.
 It will load the files from the connected storage.
 The following types of information will be extracted:
@@ -215,6 +245,7 @@ The following types of information can be extracted:
 - `IMAGE`: image found in the document
 
 For sitemap sources, additional parameters can be provided, e.g.:
+
 - `web_path`: The URL of the XML sitemap to crawl
 - `filter_urls`: JSON array of URL patterns to filter pages (optional)
 - `header_template`: JSON object for custom HTTP headers (optional)