feat(bigtable): Use connection factory to create connection and require connections to be primed. by sushanb · Pull Request #13755 · googleapis/google-cloud-go

sushanb · 2026-02-03T02:58:00Z

lift and sift of sushanb#5

gemini-code-assist · 2026-02-03T02:58:20Z

Summary of Changes

Hello @sushanb, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request significantly refactors the Bigtable connection pooling by abstracting connection creation and priming into a dedicated connectionFactory. This change centralizes critical connection setup logic, making it more robust through the introduction of a retry mechanism for priming. The BigtableChannelPool now delegates connection instantiation to this factory, leading to cleaner code and improved reliability in establishing and maintaining connections.

Highlights

Connection Factory Introduction: A new connectionFactory struct has been introduced to centralize the logic for creating and priming Bigtable connections, ensuring all connections are properly initialized before use.
Robust Connection Priming: The connectionFactory now includes a primeWithRetry method that attempts to prime connections with exponential backoff and up to 3 retries, significantly improving resilience to transient connection issues.
Refactored Connection Pool: The BigtableChannelPool has been updated to utilize the new connectionFactory for all connection creation scenarios, including initial pool setup, connection replacement, and scaling up, simplifying its internal implementation.
Enhanced Test Infrastructure: The fakeService in test helpers has been modified to support simulating multiple priming errors, and new test cases have been added to thoroughly validate the connectionFactory's retry mechanism and context handling.

Changelog

bigtable/go.mod
- Added github.com/googleapis/gax-go/v2 dependency.
- Introduced a duplicate toolchain go1.25.5 entry.
bigtable/internal/transport/connpool.go
- Defined connectionFactory struct to manage connection dialing and priming.
- Implemented newEntry method within connectionFactory to create and prime a connEntry.
- Added primeWithRetry method to connectionFactory for priming connections with exponential backoff.
- Modified BigtableChannelPool to use connectionFactory for initial connection setup, replacement, and scaling, removing direct priming calls.
bigtable/internal/transport/connpool_helper_test.go
- Replaced pingErr with pingErrs (a slice of errors) in fakeService to allow for sequential error simulation during priming.
- Updated setPingErr to accept variadic errors.
- Modified PingAndWarm to use the pingErrs slice and capture metadata only on the first call.
- Added getPingCallCount to fakeService for tracking PingAndWarm invocations.
bigtable/internal/transport/connpool_synctest_test.go
- Imported google.golang.org/grpc/codes, google.golang.org/grpc/metadata, and google.golang.org/grpc/status.
- Added TestConnectionFactoryWithSyncTest to test connectionFactory behavior, particularly concerning context timeouts during backoff.
bigtable/internal/transport/connpool_test.go
- Introduced TestConnectionFactory with comprehensive test cases for various scenarios, including successful priming, dial errors, successful retries, failed retries, and context cancellation.
- Adjusted existing tests (TestBigtableConn_Prime, TestReplaceConnection, TestAddConnections) to integrate with the new connectionFactory and fakeService changes.

Activity

The changes in this pull request are a 'lift and sift' (re-application and adaptation) of work previously done in feat(bigtable): Use connection factory to create connection and require connections to be primd. sushanb/google-cloud-go#5.

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Code Review

This pull request refactors the connection creation logic by introducing a connectionFactory. This is a great improvement as it centralizes connection creation and priming, and adds retry logic with backoff for priming connections, making the connection pool more robust. The changes are well-tested with updates to existing tests and new tests for the factory.

I've found a couple of minor issues: a duplicated line in go.mod and a leftover debug print statement in the new connection factory logic. Please see the detailed comments.

nimf

LGTM

nimf · 2026-02-05T01:17:25Z

+		wantPrimeCalls int
+	}{
+		{
+			name:        "Timeout During Backoff",


why this one is in connpool_synctest_test and the others in connpool_test?

PR created by the Librarian CLI to initialize a release. Merging this PR will auto trigger a release. Librarian Version: v0.8.0 Language Image: us-central1-docker.pkg.dev/cloud-sdk-librarian-prod/images-prod/librarian-go@sha256:19bb93e8f1f916c61b597db2bad65dc432f79baaabb210499d7d0e4ad1dffe29 <details><summary>bigtable: 1.43.0</summary> ## [1.43.0](bigtable/v1.42.0...bigtable/v1.43.0) (2026-03-16) ### Features * Add support for creating Instance with tags (#13459) ([1bce843](1bce843e)) * support tiered storage (#13793) ([39a25b9](39a25b92)) * add handling of longupdown metrics aka gauge (#13871) ([519ed9b](519ed9b0)) * Use direct access when supported. Guarded by enabling… (#13873) ([5ea1f5f](5ea1f5f9)) * add preemptive connection recycler (#13860) ([6b69ee3](6b69ee38)) * make downscalling less aggressive (#14123) ([7ac72cc](7ac72cc8)) * add pacemaker in connpool (#13862) ([9af047f](9af047f7)) * populate ip protocol for direct access checker and rename a method to be concise (#14011) ([9c5e655](9c5e6551)) * add connection factory to abstract connection (#13755) ([b08ea15](b08ea15f)) * make pow of 2 default lb policy (#14131) ([b5f7bf2](b5f7bf27)) * derive conn pool from resolver (#14147) ([b903e29](b903e299)) * add load balancing penalty for channel (#14149) ([bb64998](bb649988)) * cap increase in conn for dynamic chan pool (#14144) ([e0701a4](e0701a46)) * switch to rand v2 (#14008) ([ee6f425](ee6f4251)) ### Bug Fixes * slighly change instruction for direct access (#14119) ([7dd4948](7dd4948d)) * refactor bigtable.go into separate file path per interfaces (#13818) ([c8ae2e2](c8ae2e2a)) </details>

sushanb requested review from a team and nimf February 3, 2026 02:58

sushanb requested a review from a team as a code owner February 3, 2026 02:58

product-auto-label Bot added the api: bigtable Issues related to the Bigtable API. label Feb 3, 2026

gemini-code-assist Bot reviewed Feb 3, 2026

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Comment thread bigtable/internal/transport/connpool.go Outdated

Comment thread bigtable/go.mod Outdated

sushanb requested a review from a team as a code owner February 4, 2026 02:11

nimf approved these changes Feb 5, 2026

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sushanb force-pushed the prime_ branch from 9b64182 to 961a2a7 Compare February 6, 2026 02:41

nimf reviewed Feb 6, 2026

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Comment thread bigtable/internal/transport/connpool_test.go

nimf approved these changes Feb 6, 2026

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sushanb added 13 commits February 6, 2026 19:39

feat(bigtable): add client startup time metrics

5d02049

fix

f6daa3a

address review

e797768

add synctest

2096662

add synctest

205e7b5

fix

774b15d

make kokoro happy

84c1bc0

use connection factory

970e4ac

review

5d398d8

fix

ce152b7

fix

a344426

todo

505f901

remove

6811f55

sushanb force-pushed the prime_ branch from 961a2a7 to 6811f55 Compare February 7, 2026 00:39

sushanb merged commit b08ea15 into googleapis:main Feb 7, 2026
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bhshkh mentioned this pull request Mar 16, 2026

chore: librarian release pull request: 20260316T221702Z #14185

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feat(bigtable): Use connection factory to create connection and require connections to be primed.#13755

feat(bigtable): Use connection factory to create connection and require connections to be primed.#13755
sushanb merged 13 commits intogoogleapis:mainfrom
sushanb:prime_

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sushanb commented Feb 3, 2026

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