[Internal] DTS: Adds logic to merge session data from DTC response into SessionContainer by Meghana-Palaparthi · Pull Request #5705 · Azure/azure-cosmos-dotnet-v3

Meghana-Palaparthi · 2026-03-19T00:34:44Z

Pull Request Template

Description

After a CommitDistributedTransaction, per-operation session tokens in the JSON response body were never pushed into the SDK's SessionContainer. Subsequent reads with Session consistency on the affected collections could therefore fail with ReadSessionNotAvailable (404/1002).

Changes:

DistributedTransactionCommitter: add MergeSessionTokens() private helper, called after FromResponseMessageAsync returns. Iterates (result[i], operation[i]) pairs, builds a minimal header collection carrying the per-operation session token, and calls sessionContainer.SetSessionToken(collectionRid, collectionFullname, headers) mirroring the pattern used by GatewayStoreModel.CaptureSessionTokenAndHandleSplitAsync() for TransactionalBatch.
New unit tests in DistributedTransactionCommitterTests
Merge session data from DTC response into SessionContainer

Type of change

Please delete options that are not relevant.

[] Bug fix (non-breaking change which fixes an issue)
[] New feature (non-breaking change which adds functionality)
[] Breaking change (fix or feature that would cause existing functionality to not work as expected)
[] This change requires a documentation update

Closing issues

To automatically close an issue: closes #IssueNumber

After a CommitDistributedTransaction, per-operation session tokens in the JSON response body were never pushed into the SDK's SessionContainer. Subsequent reads with Session consistency on the affected collections could therefore fail with ReadSessionNotAvailable (404/1002). Changes: - DistributedTransactionCommitter: add MergeSessionTokens() private helper, called after FromResponseMessageAsync returns. Iterates (result[i], operation[i]) pairs, builds a minimal header collection carrying the per-operation session token, and calls sessionContainer.SetSessionToken(collectionRid, collectionFullname, headers) mirroring the pattern used by GatewayStoreModel.CaptureSessionTokenAndHandleSplitAsync for TransactionalBatch. - DistributedTransactionOperationResult (pre-existing bugs uncovered by tests): * Change [JsonConstructor] constructor from protected to public System.Text.Json reflection mode requires a public constructor. * Change ResourceBodyBase64 from internal to public [JsonInclude] members must be public in reflection mode. - New unit tests in DistributedTransactionCommitterTests: * MergesSessionTokensIntoSessionContainer * SkipsMerge_WhenSessionTokenIsNull * PassesCorrectCollectionToSetSessionToken (multi-collection, Mock<ISessionContainer>) * MergesSessionTokens_OnFailureResponse Merge session data from DTC response into SessionContainer After a CommitDistributedTransaction, per-operation session tokens in the JSON response body were never pushed into the SDK's SessionContainer. Subsequent reads with Session consistency on the affected collections could therefore fail with ReadSessionNotAvailable (404/1002). Changes: - DistributedTransactionCommitter: add MergeSessionTokens() private helper, called after FromResponseMessageAsync returns. Iterates (result[i], operation[i]) pairs, builds a minimal header collection carrying the per-operation session token, and calls sessionContainer.SetSessionToken(collectionRid, collectionFullname, headers) mirroring the pattern used by GatewayStoreModel.CaptureSessionTokenAndHandleSplitAsync for TransactionalBatch. - DistributedTransactionOperationResult (pre-existing bugs uncovered by tests): * Change [JsonConstructor] constructor from protected to public System.Text.Json reflection mode requires a public constructor. * Change ResourceBodyBase64 from internal to public [JsonInclude] members must be public in reflection mode. - New unit tests in DistributedTransactionCommitterTests: * MergesSessionTokensIntoSessionContainer * SkipsMerge_WhenSessionTokenIsNull * PassesCorrectCollectionToSetSessionToken (multi-collection, Mock<ISessionContainer>) * MergesSessionTokens_OnFailureResponse Co-Authored-By: Copilot <223556219+Copilot@users.noreply.github.com>

into users/Meghana-Palaparthi/dtc-session-merge

kirankumarkolli · 2026-03-24T18:04:08Z

+                headers.Clear();
+                headers[HttpConstants.HttpHeaders.SessionToken] = result.SessionToken;
+
+                sessionContainer.SetSessionToken(


Optimization: Each operation inside does a locking, wondering if a new API for batch updates for a collection will help.

/cc: @FabianMeiswinkel

Can you please create a follow-up GitHub issue to track it.

Created a GitHub issue: #5729

kirankumarkolli

Waiting for Exclude sessionCapture for 404/1002

- Exclude 404/ReadSessionNotAvailable from session token capture in MergeSessionTokens, mirroring GatewayStoreModel.CaptureSessionTokenAndHandleSplitAsync. A 404/1002 response means the session was not found, so merging such a token would propagate stale data. - Add [JsonInclude] and public getter to SubStatusCode so STJ reflection mode can deserialize per-operation sub-status codes from the DTC JSON response body (required for the 404/1002 check above). - Add a note about the per-call locking in SetSessionToken as a future optimization opportunity. - Clarify the ResourceBodyBase64 XML doc: explains why it must be public (STJ reflection mode requires [JsonInclude] members to be public) and why the base64 decoding logic is needed (DTC server encodes resource bodies as base64 in the JSON response).

kirankumarkolli · 2026-04-01T22:13:15Z

+                    }
+                    catch (Exception ex)
+                    {
+                        DefaultTrace.TraceWarning($"DTC session token merge failed (non-fatal): {ex.Message}");


What are the possible errors and is ignoring fine?
Can you please validate similar flows

DTS commit has already succeeded on the server, so a failure here should not propagate back to the caller as a transaction error. That's why we are ignoring it here. If we want to propagate it, then we need to make it clear that the DTS commit has succeeded and there's an error during session token merge.

Possible exceptions:

IndexOutOfRangeException / FormatException from SessionContainer.SetSessionToken if the server returns a malformed session token.

FormatException from ResourceId.Parse if the collection RID is malformed.

GatewayStoreModel.CaptureSessionTokenAndHandleSplitAsync does NOT wrap SetSessionToken in a try/catch, so an exception there would propagate even though the server write already succeeded.

That's a good call out and for now we can continue with current model and let the call stack covey the failure. Lets also please track this work item.

Very little value with tracing as CX already sees the final failure. try-catch is not really needed.

kirankumarkolli · 2026-04-02T21:21:51Z

            requestMessage.UseGatewayMode = true;
        }

+        internal static void MergeSessionTokens(


Optimization: Follow-up limit session merge for only SESSION, MM

…github.com/Azure/azure-cosmos-dotnet-v3 into users/Meghana-Palaparthi/dtc-session-merge

Meghana-Palaparthi and others added 2 commits March 18, 2026 19:25

Merge branch 'master' of https://github.com/Azure/azure-cosmos-dotnet-v3

8508fe7

into users/Meghana-Palaparthi/dtc-session-merge

Meghana-Palaparthi marked this pull request as ready for review March 19, 2026 00:35

Meghana-Palaparthi requested review from FabianMeiswinkel, Pilchie, adityasa, khdang, kirankumarkolli, kirillg, neildsh and sboshra as code owners March 19, 2026 00:35

kirankumarkolli reviewed Mar 24, 2026

View reviewed changes

Comment thread Microsoft.Azure.Cosmos/src/DistributedTransaction/DistributedTransactionOperationResult.cs Outdated

kirankumarkolli reviewed Mar 24, 2026

View reviewed changes

Comment thread Microsoft.Azure.Cosmos/src/DistributedTransaction/DistributedTransactionCommitter.cs

kirankumarkolli reviewed Mar 24, 2026

View reviewed changes

Merge branch 'master' into users/Meghana-Palaparthi/dtc-session-merge

6387d62

kirankumarkolli requested changes Apr 1, 2026

View reviewed changes

Meghana-Palaparthi added 2 commits April 1, 2026 14:11

Merge branch 'master' into users/Meghana-Palaparthi/dtc-session-merge

081c9d3

kirankumarkolli reviewed Apr 1, 2026

View reviewed changes

Comment thread Microsoft.Azure.Cosmos/src/DistributedTransaction/DistributedTransactionCommitter.cs Outdated

kirankumarkolli reviewed Apr 1, 2026

View reviewed changes

Comment thread Microsoft.Azure.Cosmos/src/DistributedTransaction/DistributedTransactionCommitter.cs Outdated

Meghana-Palaparthi mentioned this pull request Apr 2, 2026

SessionContainer Optimization: Adds batch SetSessionTokens API to reduce lock acquisitions on multi-operation responses #5729

Open

Meghana-Palaparthi added 2 commits April 2, 2026 15:32

Merge branch 'master' into users/Meghana-Palaparthi/dtc-session-merge

d7b6a03

Address feedback

68a6fd6

kirankumarkolli reviewed Apr 2, 2026

View reviewed changes

Comment thread Microsoft.Azure.Cosmos/src/DistributedTransaction/DistributedTransactionCommitter.cs Outdated

kirankumarkolli reviewed Apr 2, 2026

View reviewed changes

Meghana-Palaparthi added 3 commits April 3, 2026 10:26

Address feedback: move validations to response building

c86579d

Merge branch 'master' into users/Meghana-Palaparthi/dtc-session-merge

92f75ac

resolve merge conflicts and address feedback

e217d8a

Meghana-Palaparthi requested a review from kirankumarkolli April 3, 2026 18:17

kirankumarkolli previously approved these changes Apr 3, 2026

View reviewed changes

Update DistributedTransactionSerializerTests.cs

b78f663

Meghana-Palaparthi dismissed kirankumarkolli’s stale review via b78f663 April 3, 2026 20:33

Meghana-Palaparthi added 3 commits April 6, 2026 09:29

Merge branch 'master' into users/Meghana-Palaparthi/dtc-session-merge

52ae176

Update DistributedWriteTransactionTests.cs

1302d61

Merge branch 'users/Meghana-Palaparthi/dtc-session-merge' of https://…

07c97c3

…github.com/Azure/azure-cosmos-dotnet-v3 into users/Meghana-Palaparthi/dtc-session-merge

kirankumarkolli approved these changes Apr 6, 2026

View reviewed changes

kirankumarkolli merged commit 7d03aa0 into master Apr 6, 2026
32 checks passed

kirankumarkolli deleted the users/Meghana-Palaparthi/dtc-session-merge branch April 6, 2026 23:26

NaluTripician mentioned this pull request May 12, 2026

[Internal] DTS: Adds partitionKeyRangeId to operation result to assemble valid session tokens in DTS #5856

Merged

1 task

adamnova mentioned this pull request May 28, 2026

Client Encryption: Adds streaming JSON processing support to feed iterators #5907

Closed

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

[Internal] DTS: Adds logic to merge session data from DTC response into SessionContainer#5705

[Internal] DTS: Adds logic to merge session data from DTC response into SessionContainer#5705
kirankumarkolli merged 14 commits into
masterfrom
users/Meghana-Palaparthi/dtc-session-merge

Meghana-Palaparthi commented Mar 19, 2026

Uh oh!

Uh oh!

Uh oh!

kirankumarkolli Mar 24, 2026

Uh oh!

kirankumarkolli Apr 2, 2026

Uh oh!

Meghana-Palaparthi Apr 2, 2026

Uh oh!

kirankumarkolli left a comment

Uh oh!

kirankumarkolli Apr 1, 2026

Uh oh!

Meghana-Palaparthi Apr 2, 2026

Uh oh!

kirankumarkolli Apr 2, 2026

Uh oh!

kirankumarkolli Apr 3, 2026

Uh oh!

Uh oh!

Uh oh!

Uh oh!

kirankumarkolli Apr 2, 2026

Uh oh!

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

2 participants

Conversation

Meghana-Palaparthi commented Mar 19, 2026

Pull Request Template

Description

Type of change

Closing issues

Uh oh!

Uh oh!

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

kirankumarkolli left a comment

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

2 participants