Add SAI generate debug dump HLD

doc/SAI_generate_debug_dump/SAI_generate_debug_dump.md

@@ -0,0 +1,115 @@
+# SYNCD Optimization for SONiC
+
+## Table of Contents
+
+- [SYNCD Optimization for SONiC](#syncd-optimization-for-sonic)
+  - [Table of Contents](#table-of-contents)
+    - [Revision](#revision)
+    - [Scope](#scope)
+    - [Terminology](#terminology)
+    - [Overview](#overview)
+    - [Requirements](#requirements)
+    - [Architecture Design](#architecture-design)
+    - [Implementation](#implementation)
+	  - [sonic-utilities](#sonic-utilities)
+	  - [SWSS](#SWSS)
+	  - [SWSS-common](#SWSS-common)
+	  - [SAI-Redis](#SAI-Redis)
+      - [SAI API](#sai-api)
+      - [YANG model changes](#yang-model-changes)
+      - [CLI](#cli)
+	- [Warmboot and Fastboot Design Impact]
+	- [Testing Requirements/Design]
+	- [Unit Test cases]
+	- [System Test cases]
+
+### Revision
+
+| Rev |   Date   |          Author           | Change Description |
+| :-: | :------: | :-----------------------: | ------------------ |
+| 0.1 | 10/15/24 | Aviram Dali (**Marvell**) | Initial Draft      |
+
+### Scope
+
+The scope of this document is to design the handling of taking a SAI dump during show techsupport call 
+
+### Terminology
+
+| Term      | Definition                              |
+| --------- | --------------------------------------- |
+| ASIC      | Application Specific Integrated Circuit |
+| SYNCD     | ASIC Synchronization Service            |
+| SAI       | Switch Abstraction Interface            |
+| API       | Application Programmable Interface      |
+| SWSS      | Switch State Service                    |
+
+
+### Overview
+SAI dump file usually includes, SDK info and configuration , SAI stats, capture of SAI lower layer states like registers vales etc...
+Currently, the SAI dump file is generated only during SAI failures by executing a dedicated executable named "saidump", which linkage with the SAI lib during initialization it creates a new switch in redundant mode. This new feature allows users to generate a SAI debug dump file using command such as show tech-support not necessarily during failure, and the dump file will be generated directly from the syncd process. 
+
+
+### Requirements
+Each vendor can add to its specific implantation part of the `show techsupport` a simple call to a new API to generate the SAI debug dump file.
+
+### Architecture Design
+
+1. A user command, such as `show techsupport` triggers the `generate_sai_dump` bash script, which writes the file name to the STATE DB.
+2. A new orchestration agent, `DbgGenDumpOrch`, is triggered to handle the request.
+3. `DbgGenDumpOrch` writes the file name to the ASIC DB and sets a new operation `REDIS_ASIC_STATE_COMMAND_DBG_GEN_DUMP` for syncd.
+4. Syncd calls the global SAI API `dbgGenerateDump` to generate the debug dump file, which is saved in syncd's file system.
+5. Syncd sends a reply back to `DbgGenDumpOrch`.
+6. `DbgGenDumpOrch` analyzes the response.
+7. `DbgGenDumpOrch` updates the result in the STATE DB.
+8. The user command retrieves the result.
+9. The debug dump file is pulled on success.
+
+The below diagram explains the sequence when a SAI failure happens
+![](/images/generate_debug_dump_file.JPG)
+
+
+### Implementation
+
+#### sonic-utilities
+Add a new script to the Debian file system named `gen_sai_dbg_dump_lib.sh`, which includes the `generate_sai_dump` API. This function takes the desired file name as an argument and initiates the generation of a SAI debug dump file by performing the following steps:
+
+- Set the file name in the STATE DB to trigger the dump generation.
+- Poll the STATE DB for the result with timeout of 10 seconds.
+- Delete the relevant entries from the STATE DB after triggering the dump file.
+- Ensure that the generated file exists.
+
+
+**Show Techsupport**  
+- Introduced a new generic API, `generate_sai_dbg_dump_file`, in `generate_dump.sh` (invoked by the "show techsupport" command) to create a debug dump file. This change allows each vendor to call this API in their vendor-specific implementation
+- After the file is generated, it is moved into the techsupport folder.
+
+#### SWSS
+- A new orchestration agent, `DbgGenDumpOrch`, has been introduced, which is triggered by updates in the STATE DB.
+- It updates syncd by writing to the ASIC DB and waits for a response. Once received, it writes the result back to the STATE DB, allowing the calling application to retrieve the file.
+
+#### SWSS-common
+- add new tables name 
+
+#### SAI-Redis
+- Implemented a new global API, `dbgGenerateDump`, in the `SaiInterface` class, ensuring that all derived classes provide the corresponding implementation, including the vendor SAI class to call the global API `sai_dbg_generate_dump`.
+- Added a new syncd operation, `REDIS_ASIC_STATE_COMMAND_DBG_GEN_DUMP`, which invokes the SAI API to generate the debug dump file.
+
+#### SAI API
+There are currently no new SAI APIs required for this feature.
+
+#### YANG model changes
+No Changes.
+
+#### CLI
+No changes.
+
+### Warmboot and Fastboot Design Impact
+There is no impact on warmboot or fastboot
+
+### Testing Requirements/Design
+
+#### Unit Test cases
+
+#### System Test cases
+Verify if the dump in techsupport contains the SAI failure dump is collected.
+