psud: Adding Redis Pipeline for performance improvement by GauravNagesh · Pull Request #711 · sonic-net/sonic-platform-daemons

GauravNagesh · 2025-11-19T05:56:43Z

Description

This PR introduces significant performance improvements to the PSU daemon by optimizing Redis database operations through batching. The key change is Batching.

The daemon now uses RedisPipeline, which instead of sending 1 request separately each time, batches multiple Redis request together and sends them. Also flushes any unfilled batches at the end of each monitoring cycle if any requests still remain. This reduces the number of round trips to the Redis database.

Additionally, existing tests were updated to include above change changes and to mock the new RedisPipeline and FieldValuePairs constructors.

Motivation and Context

Why RedisPipeline and Batching :
Currently, the psud daemon creates and maintains a separate db connection internally for each table used and an additional initial connection to state_db as shown here Table Constructor and RedisPipeline Constructor

So in total we maintain 5 separate Redis database connections in psud (1 connection each for CHASSIS_INFO_TABLE, PSU_INFO_TABLE, FAN_INFO_TABLE, PHYSICAL_ENTITY_INFO_TABLE and the initial connection to STATE_DB) which is waste of Redis and system resources. Moreover, since psud purely a single process executing all requests in a sequential manner, we don't need multiple connections. Just one connection shared across all the tables is sufficient.

Also in the existing flow, individual set() calls are made for each device and their attribute. Rather we can collect all device data in batches using RedisPipeline and then do a single bulk update, which will be faster.

We can also optimize database cleanup operations, where we do multiple individual delete operations in __del__ method for each table key across all tables. Rather we can also batch the delete operations using RedisPipeline for faster cleanup during daemon shutdown, which will be quick in signal handling and reboot scenarios.

Overall benefit :

Reduced IO network overhead by batching requests
Reduced Redis and system system resources by reusing the same connection for RedisPipeline rather than having a seperate connection to Redis for each table

How Has This Been Tested?

The changes were tested on both virtual and physical platforms. Performance benchmarking was conducted to compare the baseline and the updated implementation, capturing relevant metrics across all database operations.

Additional Information (Optional)

mssonicbld · 2025-11-19T05:56:50Z

/azp run

azure-pipelines · 2025-11-19T05:56:59Z

Azure Pipelines successfully started running 1 pipeline(s).

GauravNagesh · 2025-11-20T07:21:36Z

/azpw run

mssonicbld · 2025-11-20T07:21:39Z

/AzurePipelines run

azure-pipelines · 2025-11-20T07:21:48Z

Azure Pipelines successfully started running 1 pipeline(s).

mssonicbld · 2025-11-20T08:43:59Z

/azp run

azure-pipelines · 2025-11-20T08:44:08Z

Azure Pipelines successfully started running 1 pipeline(s).

mssonicbld · 2025-11-21T07:36:14Z

/azp run

azure-pipelines · 2025-11-21T07:36:23Z

Azure Pipelines successfully started running 1 pipeline(s).

Copilot

Pull request overview

This PR introduces performance optimizations to the PSU daemon by implementing Redis batching through RedisPipeline. Instead of maintaining separate database connections for each table and sending individual requests, the daemon now uses a shared RedisPipeline instance that batches multiple operations together before flushing them to STATE_DB.

Key changes:

Replaced individual Table connections with a shared RedisPipeline instance (batch_size=10)
Added periodic pipeline flush at the end of each monitoring cycle with exception handling
Updated test mocks to support the new RedisPipeline and buffered Table constructors

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 9 comments.

File	Description
sonic-psud/scripts/psud	Implemented RedisPipeline for batching database operations across all tables and added flush logic with error handling in the main run loop
sonic-psud/tests/test_DaemonPsud.py	Added test coverage for Redis pipeline flush exception scenario
sonic-psud/tests/mocked_libs/swsscommon/swsscommon.py	Added RedisPipeline mock class and updated Table mock to support both legacy and buffered constructors

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Copilot · 2025-11-26T16:24:47Z

        if self.first_run:
            self.first_run = False

+        # flush any remaining requests on the pipeline to STAT_DB at end of every cycle


Typo in comment: "STAT_DB" should be "STATE_DB" to match the actual database name used throughout the codebase.

Suggested change

# flush any remaining requests on the pipeline to STAT_DB at end of every cycle

# flush any remaining requests on the pipeline to STATE_DB at end of every cycle

Copilot · 2025-11-26T16:24:47Z

 class Table:
-    def __init__(self, db, table_name):
+    def __init__(self,  db_or_pipeline, table_name, buffered=False):
+        # Mock to support both both constructors (db, table_name) and (pipeline, table_name, buffered)


Duplicate word in comment: "both both" should be "both".

Suggested change

# Mock to support both both constructors (db, table_name) and (pipeline, table_name, buffered)

# Mock to support both constructors (db, table_name) and (pipeline, table_name, buffered)

Copilot · 2025-11-26T16:24:47Z

        daemon_psud.run()
        assert daemon_psud.first_run is False


The test should verify that statedb_redisPipeline.flush() is called during the successful execution path. Currently, only the exception scenario is explicitly tested. Consider adding an assertion like daemon_psud.statedb_redisPipeline.flush.assert_called() after line 108 to verify the flush operation is invoked in the normal case.

Copilot · 2025-11-26T16:24:48Z


 class Table:
-    def __init__(self, db, table_name):
+    def __init__(self,  db_or_pipeline, table_name, buffered=False):


Extra whitespace before parameter: there are two spaces before db_or_pipeline. Remove one space for consistent formatting.

Suggested change

def __init__(self, db_or_pipeline, table_name, buffered=False):

def __init__(self, db_or_pipeline, table_name, buffered=False):

Copilot · 2025-11-26T16:24:48Z

+        self.chassis_tbl = swsscommon.Table(self.statedb_redisPipeline, CHASSIS_INFO_TABLE, True)
+        self.psu_tbl = swsscommon.Table(self.statedb_redisPipeline, PSU_INFO_TABLE, True)
+        self.fan_tbl = swsscommon.Table(self.statedb_redisPipeline, FAN_INFO_TABLE, True)
+        self.phy_entity_tbl = swsscommon.Table(self.statedb_redisPipeline, PHYSICAL_ENTITY_INFO_TABLE, True)


Call to Table.init with too many arguments; should be no more than 2.
Call to Table.init with too many arguments; should be no more than 2.
Call to Table.init with too many arguments; should be no more than 2.
Call to Table.init with too many arguments; should be no more than 2.

Suggested change

self.chassis_tbl = swsscommon.Table(self.statedb_redisPipeline, CHASSIS_INFO_TABLE, True)

self.psu_tbl = swsscommon.Table(self.statedb_redisPipeline, PSU_INFO_TABLE, True)

self.fan_tbl = swsscommon.Table(self.statedb_redisPipeline, FAN_INFO_TABLE, True)

self.phy_entity_tbl = swsscommon.Table(self.statedb_redisPipeline, PHYSICAL_ENTITY_INFO_TABLE, True)

self.chassis_tbl = swsscommon.Table(self.statedb_redisPipeline, CHASSIS_INFO_TABLE)

self.psu_tbl = swsscommon.Table(self.statedb_redisPipeline, PSU_INFO_TABLE)

self.fan_tbl = swsscommon.Table(self.statedb_redisPipeline, FAN_INFO_TABLE)

self.phy_entity_tbl = swsscommon.Table(self.statedb_redisPipeline, PHYSICAL_ENTITY_INFO_TABLE)

This parameter is needed for the Redis Pipeline implementation and the Table constructor actually does allow these arguments as shown here Table Constructor

Copilot · 2025-11-26T16:24:48Z

+        self.chassis_tbl = swsscommon.Table(self.statedb_redisPipeline, CHASSIS_INFO_TABLE, True)
+        self.psu_tbl = swsscommon.Table(self.statedb_redisPipeline, PSU_INFO_TABLE, True)
+        self.fan_tbl = swsscommon.Table(self.statedb_redisPipeline, FAN_INFO_TABLE, True)
+        self.phy_entity_tbl = swsscommon.Table(self.statedb_redisPipeline, PHYSICAL_ENTITY_INFO_TABLE, True)


Call to Table.init with too many arguments; should be no more than 2.
Call to Table.init with too many arguments; should be no more than 2.
Call to Table.init with too many arguments; should be no more than 2.
Call to Table.init with too many arguments; should be no more than 2.

Suggested change

self.chassis_tbl = swsscommon.Table(self.statedb_redisPipeline, CHASSIS_INFO_TABLE, True)

self.psu_tbl = swsscommon.Table(self.statedb_redisPipeline, PSU_INFO_TABLE, True)

self.fan_tbl = swsscommon.Table(self.statedb_redisPipeline, FAN_INFO_TABLE, True)

self.phy_entity_tbl = swsscommon.Table(self.statedb_redisPipeline, PHYSICAL_ENTITY_INFO_TABLE, True)

self.chassis_tbl = swsscommon.Table(self.statedb_redisPipeline, CHASSIS_INFO_TABLE)

self.psu_tbl = swsscommon.Table(self.statedb_redisPipeline, PSU_INFO_TABLE)

self.fan_tbl = swsscommon.Table(self.statedb_redisPipeline, FAN_INFO_TABLE)

self.phy_entity_tbl = swsscommon.Table(self.statedb_redisPipeline, PHYSICAL_ENTITY_INFO_TABLE)

This parameter is needed for the Redis Pipeline implementation and the Table constructor actually does allow these arguments as shown here Table Constructor

Copilot · 2025-11-26T16:24:48Z

+        self.chassis_tbl = swsscommon.Table(self.statedb_redisPipeline, CHASSIS_INFO_TABLE, True)
+        self.psu_tbl = swsscommon.Table(self.statedb_redisPipeline, PSU_INFO_TABLE, True)
+        self.fan_tbl = swsscommon.Table(self.statedb_redisPipeline, FAN_INFO_TABLE, True)
+        self.phy_entity_tbl = swsscommon.Table(self.statedb_redisPipeline, PHYSICAL_ENTITY_INFO_TABLE, True)


Call to Table.init with too many arguments; should be no more than 2.
Call to Table.init with too many arguments; should be no more than 2.
Call to Table.init with too many arguments; should be no more than 2.
Call to Table.init with too many arguments; should be no more than 2.

Suggested change

self.chassis_tbl = swsscommon.Table(self.statedb_redisPipeline, CHASSIS_INFO_TABLE, True)

self.psu_tbl = swsscommon.Table(self.statedb_redisPipeline, PSU_INFO_TABLE, True)

self.fan_tbl = swsscommon.Table(self.statedb_redisPipeline, FAN_INFO_TABLE, True)

self.phy_entity_tbl = swsscommon.Table(self.statedb_redisPipeline, PHYSICAL_ENTITY_INFO_TABLE, True)

self.chassis_tbl = swsscommon.Table(self.statedb_redisPipeline, CHASSIS_INFO_TABLE)

self.psu_tbl = swsscommon.Table(self.statedb_redisPipeline, PSU_INFO_TABLE)

self.fan_tbl = swsscommon.Table(self.statedb_redisPipeline, FAN_INFO_TABLE)

self.phy_entity_tbl = swsscommon.Table(self.statedb_redisPipeline, PHYSICAL_ENTITY_INFO_TABLE)

This parameter is needed for the Redis Pipeline implementation and the Table constructor actually does allow these arguments as shown here Table Constructor

Copilot · 2025-11-26T16:24:49Z

+        self.chassis_tbl = swsscommon.Table(self.statedb_redisPipeline, CHASSIS_INFO_TABLE, True)
+        self.psu_tbl = swsscommon.Table(self.statedb_redisPipeline, PSU_INFO_TABLE, True)
+        self.fan_tbl = swsscommon.Table(self.statedb_redisPipeline, FAN_INFO_TABLE, True)
+        self.phy_entity_tbl = swsscommon.Table(self.statedb_redisPipeline, PHYSICAL_ENTITY_INFO_TABLE, True)


Call to Table.init with too many arguments; should be no more than 2.
Call to Table.init with too many arguments; should be no more than 2.
Call to Table.init with too many arguments; should be no more than 2.
Call to Table.init with too many arguments; should be no more than 2.

Suggested change

self.chassis_tbl = swsscommon.Table(self.statedb_redisPipeline, CHASSIS_INFO_TABLE, True)

self.psu_tbl = swsscommon.Table(self.statedb_redisPipeline, PSU_INFO_TABLE, True)

self.fan_tbl = swsscommon.Table(self.statedb_redisPipeline, FAN_INFO_TABLE, True)

self.phy_entity_tbl = swsscommon.Table(self.statedb_redisPipeline, PHYSICAL_ENTITY_INFO_TABLE, True)

self.chassis_tbl = swsscommon.Table(self.statedb_redisPipeline, CHASSIS_INFO_TABLE)

self.psu_tbl = swsscommon.Table(self.statedb_redisPipeline, PSU_INFO_TABLE)

self.fan_tbl = swsscommon.Table(self.statedb_redisPipeline, FAN_INFO_TABLE)

self.phy_entity_tbl = swsscommon.Table(self.statedb_redisPipeline, PHYSICAL_ENTITY_INFO_TABLE)

This parameter is needed for the Redis Pipeline implementation and the Table constructor actually does allow these arguments as shown here Table Constructor

Copilot · 2025-11-26T16:24:49Z

+    def flush(self):
+        # Mock flush operation - just clear the queue
+        self.queue.clear()
+        pass


Unnecessary 'pass' statement.

Signed-off-by: GauravNagesh <gaurav.nageshm@gmail.com>

mssonicbld · 2025-12-05T22:55:54Z

/azp run

azure-pipelines · 2025-12-05T22:56:03Z

Azure Pipelines successfully started running 1 pipeline(s).

GauravNagesh added 2 commits November 21, 2025 07:23

psud: Adding Redis Pipeline for performance improvement

fb47b25

adding tests for redis pipeline flush test coverage

f728bfb

GauravNagesh force-pushed the psud-redis-pipeline branch from 0454141 to f728bfb Compare November 21, 2025 07:36

vvolam requested a review from Copilot November 26, 2025 16:21

Copilot started reviewing on behalf of vvolam November 26, 2025 16:21 View session

Copilot finished reviewing on behalf of vvolam November 26, 2025 16:23

Copilot AI reviewed Nov 26, 2025

View reviewed changes

Fix typos in the script and tests

e9d9560

Signed-off-by: GauravNagesh <gaurav.nageshm@gmail.com>

	# flush any remaining requests on the pipeline to STAT_DB at end of every cycle
	# flush any remaining requests on the pipeline to STATE_DB at end of every cycle

	# Mock to support both both constructors (db, table_name) and (pipeline, table_name, buffered)
	# Mock to support both constructors (db, table_name) and (pipeline, table_name, buffered)

	def __init__(self, db_or_pipeline, table_name, buffered=False):
	def __init__(self, db_or_pipeline, table_name, buffered=False):

Conversation

GauravNagesh commented Nov 19, 2025

Description

Motivation and Context

How Has This Been Tested?

Additional Information (Optional)

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mssonicbld commented Nov 19, 2025

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