README: update readme for multiplexed sessions (#2405)

* README: update readme for multiplexed session

* 🦉 Updates from OwlBot post-processor

See https://github.com/googleapis/repo-automation-bots/blob/main/packages/owl-bot/README.md

* 🦉 Updates from OwlBot post-processor

See https://github.com/googleapis/repo-automation-bots/blob/main/packages/owl-bot/README.md

---------

Co-authored-by: Owl Bot <gcf-owl-bot[bot]@users.noreply.github.com>

Author: alkatrivedi

.github/workflows/ci.yaml

@@ -32,7 +32,7 @@ jobs:
       - uses: actions/checkout@v5
       - uses: actions/setup-node@v4
         with:
-          node-version: 22
+          node-version: 18
       - run: node --version
       - run: npm install --engine-strict
         working-directory: .github/scripts
@@ -46,7 +46,7 @@ jobs:
       - uses: actions/checkout@v5
       - uses: actions/setup-node@v4
         with:
-          node-version: 22
+          node-version: 18
       - run: npm install --engine-strict
       - run: npm test
         env:
@@ -57,7 +57,7 @@ jobs:
       - uses: actions/checkout@v5
       - uses: actions/setup-node@v4
         with:
-          node-version: 22
+          node-version: 18
       - run: npm install
       - run: npm run lint
   docs:
@@ -66,7 +66,7 @@ jobs:
       - uses: actions/checkout@v5
       - uses: actions/setup-node@v4
         with:
-          node-version: 22
+          node-version: 18
       - run: npm install
       - run: npm run docs
       - uses: JustinBeckwith/linkinator-action@v1

.github/workflows/issues-no-repro.yaml

@@ -13,7 +13,7 @@ jobs:
       - uses: actions/checkout@v5
       - uses: actions/setup-node@v4
         with:
-          node-version: 22
+          node-version: 18
       - run: npm install
         working-directory: ./.github/scripts
       - uses: actions/github-script@v7

.readme-partials.yml

@@ -2,3 +2,24 @@ introduction: |-
         [Cloud Spanner](https://cloud.google.com/spanner/docs/) is a fully managed, mission-critical, relational database service that
         offers transactional consistency at global scale, schemas, SQL (ANSI 2011 with extensions),
         and automatic, synchronous replication for high availability.
+
+body: |-
+        ## Multiplexed Sessions
+
+        Spanner's Multiplexed Sessions can now be used as an efficient alternative to the default session pool. This feature helps reduce
+        session management overhead and minimize session-related errors. Multiplexed sessions can be enabled for all transaction types via environment variables.
+
+        ### Configuration
+
+        To enable this feature, set the following environment variables to `true`:
+
+        * **For Read-Only Transactions:**
+        - `GOOGLE_CLOUD_SPANNER_MULTIPLEXED_SESSIONS`
+        * **For Partitioned Operations:**
+        - `GOOGLE_CLOUD_SPANNER_MULTIPLEXED_SESSIONS`
+        - `GOOGLE_CLOUD_SPANNER_MULTIPLEXED_SESSIONS_PARTITIONED_OPS`
+        * **For Read-Write Transactions:**
+        - `GOOGLE_CLOUD_SPANNER_MULTIPLEXED_SESSIONS`
+        - `GOOGLE_CLOUD_SPANNER_MULTIPLEXED_SESSIONS_FOR_RW`
+
+        For a detailed explanation of this feature, please refer to the [official documentation](https://cloud.google.com/spanner/docs/sessions#multiplexed_sessions).

README.md

@@ -80,7 +80,25 @@ console.log(`Query: ${rows.length} found.`);
 rows.forEach(row => console.log(row));
 
 ```
+## Multiplexed Sessions
 
+Spanner's Multiplexed Sessions can now be used as an efficient alternative to the default session pool. This feature helps reduce
+session management overhead and minimize session-related errors. Multiplexed sessions can be enabled for all transaction types via environment variables.
+
+### Configuration
+
+To enable this feature, set the following environment variables to `true`:
+
+* **For Read-Only Transactions:**
+- `GOOGLE_CLOUD_SPANNER_MULTIPLEXED_SESSIONS`
+* **For Partitioned Operations:**
+- `GOOGLE_CLOUD_SPANNER_MULTIPLEXED_SESSIONS`
+- `GOOGLE_CLOUD_SPANNER_MULTIPLEXED_SESSIONS_PARTITIONED_OPS`
+* **For Read-Write Transactions:**
+- `GOOGLE_CLOUD_SPANNER_MULTIPLEXED_SESSIONS`
+- `GOOGLE_CLOUD_SPANNER_MULTIPLEXED_SESSIONS_FOR_RW`
+
+For a detailed explanation of this feature, please refer to the [official documentation](https://cloud.google.com/spanner/docs/sessions#multiplexed_sessions).
 
 
 ## Samples