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Remove RadixTreeCache for int status and protect httpStatus short cache #10236

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Remove RadixTreeCache for int status and protect httpStatus short cache #10236

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1f2bb9e
Remove RadixTreeCache for int status and protect httpStatus short cache
amarziali Dec 18, 2025
0d51cb0
remove port cache from mongo listener
amarziali Dec 18, 2025
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4 changes: 1 addition & 3 deletions ...tstrap/src/main/java/datadog/trace/bootstrap/instrumentation/decorator/BaseDecorator.java
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Original file line number Diff line number Diff line change
@@ -1,6 +1,5 @@
package datadog.trace.bootstrap.instrumentation.decorator;

import static datadog.trace.api.cache.RadixTreeCache.PORTS;
import static datadog.trace.api.cache.RadixTreeCache.UNSET_PORT;
import static datadog.trace.bootstrap.instrumentation.java.net.HostNameResolver.hostName;

Expand Down Expand Up @@ -153,9 +152,8 @@ public AgentSpan setPeerPort(AgentSpan span, String port) {

public AgentSpan setPeerPort(AgentSpan span, int port) {
if (port > UNSET_PORT) {
span.setTag(Tags.PEER_PORT, PORTS.get(port));
span.setTag(Tags.PEER_PORT, port);
}

return span;
}

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3 changes: 1 addition & 2 deletions .../mongo-common/src/main/java/datadog/trace/instrumentation/mongo/MongoCommandListener.java
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Original file line number Diff line number Diff line change
@@ -1,7 +1,6 @@
package datadog.trace.instrumentation.mongo;

import static datadog.trace.api.Functions.UTF8_ENCODE;
import static datadog.trace.api.cache.RadixTreeCache.PORTS;
import static datadog.trace.bootstrap.instrumentation.api.AgentTracer.activateSpan;
import static datadog.trace.bootstrap.instrumentation.api.AgentTracer.activeSpan;
import static datadog.trace.bootstrap.instrumentation.api.AgentTracer.closeActive;
Expand Down Expand Up @@ -151,7 +150,7 @@ public void commandStarted(final CommandStartedEvent event) {
// may do a DNS lookup
ServerAddress serverAddress = event.getConnectionDescription().getServerAddress();
span.setTag(Tags.PEER_HOSTNAME, serverAddress.getHost())
.setTag(Tags.PEER_PORT, PORTS.get(serverAddress.getPort()))
.setTag(Tags.PEER_PORT, serverAddress.getPort())
.setTag(
Tags.DB_OPERATION,
COMMAND_NAMES.computeIfAbsent(event.getCommandName(), UTF8_ENCODE));
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12 changes: 11 additions & 1 deletion dd-trace-core/src/main/java/datadog/trace/core/DDSpanContext.java
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Original file line number Diff line number Diff line change
Expand Up @@ -1092,14 +1092,24 @@ public void processTagsAndBaggage(
samplingPriority != PrioritySampling.UNSET ? samplingPriority : getSamplingPriority(),
measured,
topLevel,
httpStatusCode == 0 ? null : HTTP_STATUSES.get(httpStatusCode),
httpStatusCode == 0 ? null : shortStatusCodeToString(httpStatusCode),
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@AlexeyKuznetsov-DD AlexeyKuznetsov-DD Jan 5, 2026

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Just curious if we can use int here too? Same as you did with port?
Or it would be a huge refactoring?

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@amarziali amarziali Jan 5, 2026

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Indeed I think it can be just an int (I see we use a short indeed) since in other parts is casted as int

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@mcculls mcculls Jan 5, 2026

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According to

dd-trace-java/dd-trace-core/src/main/java/datadog/trace/core/DDSpan.java

Line 421 in 701d1e5

// http.status is important because it is expected to be a string downstream

// http.status is important because it is expected to be a string downstream

so at this point in the metadata it should become a string I believe

// Get origin from rootSpan.context
getOrigin(),
longRunningVersion,
ProcessTags.getTagsForSerialization()));
}
}

private UTF8BytesString shortStatusCodeToString(short httpStatusCode) {
try {
return HTTP_STATUSES.get(httpStatusCode);
} catch (Throwable t) {
// RadixTreeCache seems to have issues on semeru11 - NPE on AtomicReferenceArray cas
// skip the cache in those cases and just create a String
return UTF8BytesString.create(Short.toString(httpStatusCode));
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@bric3 bric3 Dec 18, 2025

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question: Will this create too many allocations.

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@amarziali amarziali Dec 18, 2025 •
edited
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it's not supposed to fail the cache acccess. Note that this method is on the hot path when finish is called on the root span -> write is called. If this throw we might bubble the application code IMO. Better to allocate something than throw

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@dougqh dougqh Dec 18, 2025

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Is the failure constant on Semeru? Or is it sporadic?
If it is constant, we should probably detect the failure and then just bypass the cache there after.

I've started debating using UTF8BytesString for values, since we now have the UTF8 cache. I also have some evidence that some caches are doing more harm than good now.

Long term, I'm hoping that TagMap will provide a more elegant solution to these problems, but unfortunately, I'm not there yet.

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@amarziali amarziali Dec 19, 2025

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well I think more that there are no failures in the real life but only happens in CI. The stacktrace is very weird since it sounds like implying that either unsafe is null (sounds impossible) either the array is itself is null (that sounds not possible as well unless the class is unsafely allocated). In CI it passes on a retry run on a fresh JVM that looks indicating that something is gets corrupted on the used jvm? I put this catch in a defensive way - I can remove if needed

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@bric3 bric3 Dec 19, 2025

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How many semeru 11 hosts can be impacted ?

}
}

void injectW3CBaggageTags(Map<String, String> baggageItemsWithPropagationTags) {
List<String> baggageTagKeys = Config.get().getTraceBaggageTagKeys();
if (baggageTagKeys.isEmpty()) {
Expand Down
3 changes: 0 additions & 3 deletions internal-api/src/main/java/datadog/trace/api/cache/RadixTreeCache.java
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Original file line number Diff line number Diff line change
Expand Up @@ -18,9 +18,6 @@ public final class RadixTreeCache<T> {
16, 32, TO_STRING, 200, 201, 301, 307, 400, 401, 403, 404, 500, 502, 503);

public static final int UNSET_PORT = 0;
// should cover range [0, 2^16)
public static final RadixTreeCache<Integer> PORTS =
new RadixTreeCache<>(256, 256, Integer::valueOf, 80, 443, 8080);

private final int level1;
private final int level2;
Expand Down
7 changes: 0 additions & 7 deletions internal-api/src/test/groovy/datadog/trace/api/cache/RadixTreeCacheTest.groovy
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Original file line number Diff line number Diff line change
Expand Up @@ -118,13 +118,6 @@ class RadixTreeCacheTest extends DDSpecification {
})
}

def "cache ports"() {
expect:
Integer.valueOf(port) == RadixTreeCache.PORTS.get(port)
where:
port << [0, 80, 443, 4444, 8080, 65535]
}

def "cache HTTP statuses"() {
expect:
Integer.toString(status) == RadixTreeCache.HTTP_STATUSES.get(status) as String
Expand Down