[Enhancement] Support for Sending DBStats Metrics in Orchestrion Instrumentation

[moko-poi]

Description

Currently, dd-trace-go's contrib/database/sql package supports an option to send DBStats as Datadog metrics (refer to [#2303](DataDog/dd-trace-go#2303) and [PR #2543](DataDog/dd-trace-go#2543)). However, when using orchestrion, automatic instrumentation is applied, and currently, there is no way to explicitly enable the collection of DBStats metrics.

To enhance observability, we propose adding support for sending DBStats metrics within orchestrion. This would allow users to track database connection pool statistics more effectively when using automatic instrumentation.

Proposed Solution

• Introduce an option in orchestrion to enable DBStats collection.
• Ensure that enabling this feature integrates seamlessly with existing automatic instrumentation.
• Provide configuration options similar to those in contrib/database/sql.

Use Case

Developers using orchestrion for automatic database instrumentation currently lack access to DBStats metrics, which are valuable for monitoring database connection performance. Supporting this feature would align orchestrion's capabilities with contrib/database/sql and improve visibility into database behavior.

References

• Issue: [#2303](Stats from database/sql dd-trace-go#2303)
• PR: [#2543](contrib/database/sql: Submit DBStats as Datadog metrics dd-trace-go#2543)

Would love to hear thoughts from the maintainers on whether this could be implemented. Let me know if additional details are needed! 🚀

[moko-poi]

To add support for DBStats metrics in Orchestrion, I suggest the following changes:

diff --git a/internal/injector/testdata/injector/database-sql/config.yml b/internal/injector/testdata/injector/database-sql/config.yml
index 56b85c0..c059f5d 100644
--- a/internal/injector/testdata/injector/database-sql/config.yml
+++ b/internal/injector/testdata/injector/database-sql/config.yml
@@ -7,20 +7,36 @@ aspects:
       - wrap-expression:
           imports:
             sqltrace: gopkg.in/DataDog/dd-trace-go.v1/contrib/database/sql
+            os: os
           template: |-
-            sqltrace.Open(
-              {{range .AST.Args}}{{.}},
-            {{end}})
+            func() (*sql.DB, error) {
+                if os.Getenv("ENABLE_DB_STATS") == "true" {
+                    return sqltrace.Open(
+                        {{range .AST.Args}}{{.}},
+                    {{end}}, sqltrace.WithDBStats())
+                }
+                return sqltrace.Open(
+                    {{range .AST.Args}}{{.}},
+                {{end}})
+            }()
   - join-point:
       function-call: database/sql.OpenDB
     advice:
       - wrap-expression:
           imports:
             sqltrace: gopkg.in/DataDog/dd-trace-go.v1/contrib/database/sql
+            os: os
           template: |-
-            sqltrace.OpenDB(
-              {{range .AST.Args}}{{.}},
-            {{end}})
+            func() (*sql.DB, error) {
+                if os.Getenv("ENABLE_DB_STATS") == "true" {
+                    return sqltrace.OpenDB(
+                        {{range .AST.Args}}{{.}},
+                    {{end}}, sqltrace.WithDBStats())
+                }
+                return sqltrace.OpenDB(
+                    {{range .AST.Args}}{{.}},
+                {{end}})
+            }()
 syntheticReferences:
   gopkg.in/DataDog/dd-trace-go.v1/contrib/database/sql: true

This change provides a simple mechanism to enable the WithDBStats() option when the environment variable ENABLE_DB_STATS=true is set. This approach offers a straightforward implementation that can be extended in the future with configuration file support if needed.

If more detailed configuration (such as adjusting the metrics collection interval) is required, we could consider additional options. I believe starting with this simple implementation would be a good first step, but I'm open to feedback if you have other suggestions.