[DOCS] Observability - #3096
Open
chernser wants to merge 1 commit into
Open
Conversation
…umentation and partner spec
|
Client V2 CoverageCoverage Report
Class Coverage
|
JDBC V2 CoverageCoverage Report
Class Coverage
|
JDBC V1 CoverageCoverage Report
Class Coverage
|
Client V1 CoverageCoverage Report
Class Coverage
|
chernser
marked this pull request as ready for review
September 5, 2026 15:47
mshustov
reviewed
Sep 8, 2026
|
|
||
| For a complete production-style Spring Boot application demonstrating Client V2 configuration, connection pooling, trace context propagation across `@Async` boundaries, and full telemetry integration, see the `examples/demo-spring-service` module in this repository. | ||
|
|
||
| ### Client Builder Observability API |
Member
There was a problem hiding this comment.
This overlaps with docs/clickhouse-docs/client.mdx with similar content. I suggest consolidating it into a single document and referencing other pages. I’m concerned about content discrepancies over time
Contributor
Author
There was a problem hiding this comment.
@mshustov
I agree with you. Initially I was thinking this will be good to have some duplication so no context is mixed.
Will put here specific part and reference to the client document.
mshustov
reviewed
Sep 8, 2026
| .setUsername("default") | ||
| .setPassword("secret") | ||
| .setMaxConnections(50) | ||
| .setConnectionRequestTimeout(5, TimeUnit.SECONDS) |
Member
There was a problem hiding this comment.
not ChronoUnit? as per
mshustov
approved these changes
Sep 8, 2026
|
|
||
| ### HTTP Connection Pooling (`client-v2`) | ||
|
|
||
| The `Client` instance owns an internal Apache HttpClient 5 connection pool. It manages persistent HTTP connections to ClickHouse endpoints. |
Member
There was a problem hiding this comment.
should we add a link to Apache HttpClient 5 docs? one time is enough
Contributor
Author
There was a problem hiding this comment.
Why not.
I still think it will overflow context in some way and LLM will anyway search documentation by name but we will prune while testing.
|
|
||
| - **Layering:** HikariCP manages JDBC `Connection` instances, while each JDBC connection wraps a `Client` instance with its own internal HTTP socket pool. | ||
| - **Sizing Alignment:** Avoid over-allocating HikariCP connections. Because ClickHouse processes HTTP requests concurrently over pooled sockets, a smaller HikariCP pool (e.g., 10–20 connections) paired with a properly sized `Client` HTTP pool is typically optimal. | ||
| - **Connection Lifecycle:** Configure HikariCP's `maxLifetime` slightly shorter than any network or load-balancer idle timeout to prevent stale socket exceptions. |
Member
There was a problem hiding this comment.
than any network or load-balancer idle timeout to prevent stale socket exceptions.
Do we have any anecdotal values to recommend?
Contributor
Author
There was a problem hiding this comment.
good point. I will compose some example.
|
|
||
| ### 2. Correlating Application Traces with ClickHouse Server Logs (`system.query_log`) | ||
|
|
||
| **Symptom:** Need to trace an expensive or failing query from APM traces down to ClickHouse server execution logs. |
Member
There was a problem hiding this comment.
not only APM traces - any query, no?
|
|
||
| Tracing in Client V2 produces two types of spans arranged in a parent-child hierarchy: | ||
|
|
||
| 1. **Operation Span**: Represents a high-level client operation (`query <database>` or `insert <database>.<table_name>`). Started under the current thread's trace context (`Context.current()`) so that database operations join the caller's active trace span. |
Member
There was a problem hiding this comment.
(
query <database>orinsert <database>.<table_name>)
not related to this PR: there is inconsistency across language clients that we need to address. see ClickHouse/clickhouse-rs#390
Contributor
Author
There was a problem hiding this comment.
This is very related to this PR because we need to fix it right now to avoid changing names in the future.
We can easily fix insert and make it like in RS client.
The problem is with query because [10] db.operation.name: The operation name SHOULD NOT be extracted from db.query.text. and on the client it is problematic.
In RS client query seems has no value https://github.com/ClickHouse/clickhouse-rs/pull/390/changes#diff-f0c63cae3ed0328ebbe14ac22d86b43bc8a40146944b03c8326681e4f3802443R177
So we can remove it from our code also - in Java client user can customize observability attributes if needed
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
2 participants
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Summary
examples/demo-spring-serviceas showcase for observabilitydocs/integration-ops.mdas part of partner spec for operationsCloses: #2147
Checklist
Delete items not relevant to your PR: