Regroup all session creation in util get_localAPI_session or APISession class. by Ythogtha · Pull Request #129 · xcp-ng/sm

Ythogtha · 2026-03-26T14:29:59Z

New APISession class to handle lifecycle of the session, with context, or atexit handlers.
Use various originator for xapi session creation, to differentiate where they are being created.

APISession uses get_localAPI_session() for session creation, so there is only one place for session creation, using xenapi.login_with_password.
get_localAPI_session should be avoided and only remain in lcache.py.

The session originator is shown on all logs messages pertaining to sessions, in SMlog, in the format APISession [{originator}] {message}.
All login and logout messages starts with login or logout hence it is possible to count them to check if there is session leakage :

$ echo "login: $(grep -e 'APISession \[.*\] login' SMlog* | wc -l), logout: $(grep -e 'APISession \[.*\] logout' SMlog* | wc -l)"
login: 8024, logout: 8024

Millefeuille42

All good for me except the remaining import util

…on class. New APISession class to handle lifecycle of the session, with context, or atexit handlers. Use various originator for xapi session creation, to differentiate where they are being created. Signed-off-by: Arnaud Garcia-Fernandez <arnaud.garcia-fernandez@vates.tech>

Do not SMlog information when __del__ is called and the session has already been closed. Signed-off-by: Arnaud Garcia-Fernandez <arnaud.garcia-fernandez@vates.tech>

… are set. SMlogs are set to LOG_DEBUG, except on failure to create a session. Fixed some less readable code: - lcache.py: import util on top instead of inside a method - util.py; removed double tempfile import Signed-off-by: Arnaud Garcia-Fernandez <arnaud.garcia-fernandez@vates.tech>

…out calls, privatise some APISession methods. Signed-off-by: Arnaud Garcia-Fernandez <arnaud.garcia-fernandez@vates.tech>

Also fix some strings. Signed-off-by: Arnaud Garcia-Fernandez <arnaud.garcia-fernandez@vates.tech>

…in cleanup.py Due to the rebase, some old-style session management appeared, this commit makes them use the new APISession. Signed-off-by: Arnaud Garcia-Fernandez <arnaud.garcia-fernandez@vates.tech>

Wescoeur · 2026-07-28T21:35:53Z

+        api_session = util.timeout(5, util.APISession, "blktap-abort_linstor_gc")
+        session = api_session.session
        try:
            srs = util.get_linstor_srs_uuid(session)


Suggested change

api_session = util.timeout(5, util.APISession, "blktap-abort_linstor_gc")

session = api_session.session

try:

srs = util.get_linstor_srs_uuid(session)

api_session = util.timeout(5, util.APISession, "SM-blktap2-abort-linstor-gc")

try:

srs = util.get_linstor_srs_uuid(api_session.session)

Just to remove a temporary variable (and change session name to match other names and SM-blktap2 prefix). (:

"SM-blktap2-abort-linstor-gc" is not applied in new commits.

Wescoeur · 2026-07-28T21:46:12Z

        if self.session is None:
-            self.session = self.getSession()
-            self.sessionPrivate = True
+            self._api_session = util.APISession("SM-cleanup-XAPI")


I think we should standardize the names here. An "SMGC" prefix could match the existing logs. Or maybe "SM-GC" or just "GC". What do you think? @Ythogtha @Millefeuille42

I'm goign for SM-GC, and looking at all APISession being opened as SM-{something}.

Not fond of SM-GC even if more coherent with the rest, as GC related logs are identified as "SMGC" already.

Aug 4 07:29:34 r640-s1 SMGC: [2091943][MainThread] GC process exiting, no work left

If looking for anything GC related in the logs I know to check for "SMGC".

Ping @Nambrok for discussion.

Wescoeur · 2026-07-28T22:12:33Z

-            # Everything was coalescable, remove the message
-            xapi_session.xenapi.SR.remove_from_sm_config(self.xapi.srRef, VDI.DB_GC_NO_SPACE)
-            xapi_session.xenapi.message.destroy(msg_id)
+        with util.APISession("GC-check_no_space") as xapi_session:


Suggested change

with util.APISession("GC-check_no_space") as xapi_session:

with util.APISession("XXX-check-no-space") as xapi_session:

Suggested in a previous comment. 👀
But XXX because we must discuss about the prefix to use.

check-no-space with "-" is not applied in new commits.

Wescoeur · 2026-07-28T22:12:55Z

-                        ))
-                    finally:
-                        session.xenapi.session.logout()
+                with util.timeout(5), util.APISession("GC-coalescing") as session:


Same, prefix to discuss.

Reworked some APISession originator for better consistency. Removed unuseful `session` intermediate variables. Reworked restevdis to avoid a huge indentation caused by APISession, by using a function. Adds a try/finally for session.logout() in util.py#sr_get_capability(). Signed-off-by: Arnaud Garcia-Fernandez <arnaud.garcia-fernandez@vates.tech>

Signed-off-by: Arnaud Garcia-Fernandez <arnaud.garcia-fernandez@vates.tech>

Millefeuille42

OK for me if and when all pending comments are resolved.

Millefeuille42 · 2026-08-04T09:15:35Z

    def _init_executor_thread(self):
-        session = util.get_localAPI_session()
-        load = self.Load(session)
+        api_session = util.ApiSession("SM-linstorvhdutil")


I'd suggest to see if we can get automatically the file+function name in the session name, this will reduce maintenance in case of changes (see, for example it should be SM-linstorcowutil now) and also it would allow to not specify everytime the name of the sesion.

This is a suggestion but ain't blocking for me, could even be addressed in a separate PR.

I prefer having an explicit session name; logs indicating a session aren't necessarily debug logs. They serve as a label that is human-readable and can be independent of the implementation. If we want to be more precise here, it would be SM-linstor-multi-cow-util here.

Millefeuille42 · 2026-08-04T09:26:07Z

+class ApiSession(contextlib.AbstractContextManager):
+    session=None
+


Thinking about it, could it be interesting to define/override __call__ to login and return session? This would avoid the long and redundant api_session.session and reduce it to api_session().

Not sure if it's very clear and explicit when reading the code thought.

This is a non blocking comment, only putting it here to start a discussion.

I guess we can have a card about that.

Wescoeur · 2026-08-04T21:23:33Z

       <!-- Agent database query errors 150+ -->
        <code>
-                <name>APISession</name>
+                <name>ApiSession</name>


@Nambrok For additional comment.

I don't think we should change this field here (it would create a style inconsistent with the others below).

IMHO We should specify this error code in the ApiSession class in the event of a connection failure to the XAPI.

Wescoeur · 2026-08-04T21:25:48Z

-            # Everything was coalescable, remove the message
-            xapi_session.xenapi.SR.remove_from_sm_config(self.xapi.srRef, VDI.DB_GC_NO_SPACE)
-            xapi_session.xenapi.message.destroy(msg_id)
+        with util.APISession("GC-check_no_space") as xapi_session:


check-no-space with "-" is not applied in new commits.

Wescoeur · 2026-08-04T21:27:13Z

+        api_session = util.timeout(5, util.APISession, "blktap-abort_linstor_gc")
+        session = api_session.session
        try:
            srs = util.get_linstor_srs_uuid(session)


"SM-blktap2-abort-linstor-gc" is not applied in new commits.

Wescoeur · 2026-08-04T21:32:39Z

+class ApiSession(contextlib.AbstractContextManager):
+    session=None
+


I guess we can have a card about that.

Ythogtha force-pushed the agf-xapi_session_refactoring branch 12 times, most recently from 0f82c30 to be646e3 Compare April 2, 2026 05:09

Ythogtha requested review from Nambrok and Wescoeur April 2, 2026 05:10

Ythogtha force-pushed the agf-xapi_session_refactoring branch 3 times, most recently from e1507b2 to c0658d5 Compare April 2, 2026 13:45

Ythogtha force-pushed the agf-xapi_session_refactoring branch from eae5e31 to cee2b15 Compare April 21, 2026 09:35

Wescoeur requested a review from a team April 29, 2026 13:40

Wescoeur force-pushed the 3.2.12-8.3 branch 4 times, most recently from bc30ef6 to 1dfb701 Compare May 19, 2026 17:17

Ythogtha force-pushed the agf-xapi_session_refactoring branch from cee2b15 to 4a333e5 Compare May 20, 2026 16:16

Millefeuille42 requested changes May 21, 2026

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Ythogtha requested a review from Millefeuille42 May 24, 2026 16:12

Millefeuille42 approved these changes May 26, 2026

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Ythogtha force-pushed the agf-xapi_session_refactoring branch 2 times, most recently from bd3737d to 119cae3 Compare May 26, 2026 09:46

Wescoeur requested changes Jun 12, 2026

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Ythogtha force-pushed the agf-xapi_session_refactoring branch 5 times, most recently from d23fa61 to 8173b33 Compare June 23, 2026 15:22

Wescoeur force-pushed the 3.2.12-8.3 branch 5 times, most recently from 252789d to d8ca026 Compare June 25, 2026 22:04

Ythogtha changed the base branch from 3.2.12-8.3 to 3.2.12-8.3-devel June 26, 2026 14:41

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Ythogtha force-pushed the agf-xapi_session_refactoring branch from 8173b33 to 3c34049 Compare June 29, 2026 14:10

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Nambrok force-pushed the 3.2.12-8.3-devel branch from 6607beb to c4dce9e Compare July 2, 2026 14:25

Ythogtha force-pushed the agf-xapi_session_refactoring branch from 3c34049 to 95a0211 Compare July 7, 2026 10:00

Ythogtha added 6 commits July 24, 2026 10:59

unregister atexit on APISession:logout

5434904

Do not SMlog information when __del__ is called and the session has already been closed. Signed-off-by: Arnaud Garcia-Fernandez <arnaud.garcia-fernandez@vates.tech>

Name consistency, less intermediate variables, some more explicit log…

d09dd48

…out calls, privatise some APISession methods. Signed-off-by: Arnaud Garcia-Fernandez <arnaud.garcia-fernandez@vates.tech>

Make login reentrant.

b0734fa

Also fix some strings. Signed-off-by: Arnaud Garcia-Fernandez <arnaud.garcia-fernandez@vates.tech>

Migrate blktap2.py to now APISession, remove call to XAPI.getSession …

d1d6cb5

…in cleanup.py Due to the rebase, some old-style session management appeared, this commit makes them use the new APISession. Signed-off-by: Arnaud Garcia-Fernandez <arnaud.garcia-fernandez@vates.tech>

Wescoeur requested changes Jul 28, 2026

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Ythogtha force-pushed the agf-xapi_session_refactoring branch from fb254f1 to c4d891b Compare July 30, 2026 13:10

Global renaming from APISession to ApiSession.

bc80916

Signed-off-by: Arnaud Garcia-Fernandez <arnaud.garcia-fernandez@vates.tech>

Ythogtha requested a review from Wescoeur July 30, 2026 15:37

Wescoeur requested a review from Millefeuille42 August 3, 2026 14:31

Millefeuille42 approved these changes Aug 4, 2026

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Wescoeur requested changes Aug 4, 2026

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	with util.APISession("GC-check_no_space") as xapi_session:
	with util.APISession("XXX-check-no-space") as xapi_session:

		class ApiSession(contextlib.AbstractContextManager):
		session=None

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Ythogtha commented Mar 26, 2026

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