add new config property apm sampling enabled and keep legacy experimental asm standalone billing one

Author: jandro996

dd-trace-api/src/main/java/datadog/trace/api/config/GeneralConfig.java

@@ -93,6 +93,7 @@ public final class GeneralConfig {
       "telemetry.dependency.resolution.period.millis";
   public static final String AGENTLESS_LOG_SUBMISSION_LEVEL = "agentless.log.submission.level";
   public static final String AGENTLESS_LOG_SUBMISSION_URL = "agentless.log.submission.url";
+  public static final String APM_TRACING_ENABLED = "apm.tracing.enabled";
 
   private GeneralConfig() {}
 }

dd-trace-core/src/main/java/datadog/trace/common/sampling/Sampler.java

@@ -35,7 +35,7 @@ final class Builder {
     public static Sampler forConfig(final Config config, final TraceConfig traceConfig) {
       Sampler sampler;
       if (config != null) {
-        if (config.isAppSecStandaloneEnabled()) {
+        if (!config.isApmTracingEnabled()) {
           log.debug("APM is disabled. Only 1 trace per minute will be sent.");
           return new AsmStandaloneSampler(Clock.systemUTC());
         }

dd-trace-core/src/main/java/datadog/trace/common/writer/ddagent/DDAgentApi.java

@@ -112,7 +112,7 @@ public Response sendSerializedTraces(final Payload payload) {
                   (metricsEnabled && featuresDiscovery.supportsMetrics())
                           // Disabling the computation agent-side of the APM trace metrics by
                           // pretending it was already done by the library
-                          || Config.get().isAppSecStandaloneEnabled()
+                          || !Config.get().isApmTracingEnabled()
                       ? "true"
                       : "")
               .put(payload.toRequest())

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

@@ -64,7 +64,7 @@ public void setSamplingPriorityIfNecessary() {
     DDSpan rootSpan = getRootSpan();
     if (traceConfig.sampler instanceof PrioritySampler && rootSpan != null) {
       // Ignore the force-keep priority in the absence of propagated _dd.p.appsec span tag.
-      if ((Config.get().isAppSecStandaloneEnabled()
+      if ((!Config.get().isApmTracingEnabled()
               && !rootSpan.context().getPropagationTags().isAppsecPropagationEnabled())
           || rootSpan.context().getSamplingPriority() == PrioritySampling.UNSET) {
         ((PrioritySampler) traceConfig.sampler).setSamplingPriority(rootSpan);

dd-trace-core/src/main/java/datadog/trace/core/propagation/CorePropagation.java

@@ -64,7 +64,7 @@ private <C> void inject(
      * If the experimental appsec standalone feature is enabled and appsec propagation is disabled
      * (no ASM events), stop propagation
      */
-    if (Config.get().isAppSecStandaloneEnabled()
+    if (!Config.get().isApmTracingEnabled()
         && !ddSpanContext.getPropagationTags().isAppsecPropagationEnabled()) {
       return;
     }

internal-api/src/main/java/datadog/trace/api/Config.java

@@ -547,6 +547,8 @@ public static String getHostName() {
 
   private final long dependecyResolutionPeriodMillis;
 
+  private final boolean apmTracingEnabled;
+
   // Read order: System Properties -> Env Variables, [-> properties file], [-> default value]
   private Config() {
     this(ConfigProvider.createDefault());
@@ -1865,6 +1867,8 @@ PROFILING_DATADOG_PROFILER_ENABLED, isDatadogProfilerSafeInCurrentEnvironment())
           "AppSec SCA is enabled but telemetry is disabled. AppSec SCA will not work.");
     }
 
+    this.apmTracingEnabled = configProvider.getBoolean(GeneralConfig.APM_TRACING_ENABLED, true);
+
     log.debug("New instance: {}", this);
   }
 
@@ -2283,7 +2287,7 @@ public boolean isPerfMetricsEnabled() {
 
   public boolean isTracerMetricsEnabled() {
     // When ASM Standalone Billing is enabled metrics should be disabled
-    return tracerMetricsEnabled && !isAppSecStandaloneEnabled();
+    return tracerMetricsEnabled && isApmTracingEnabled();
   }
 
   public boolean isTracerMetricsBufferingEnabled() {
@@ -3364,6 +3368,10 @@ public String getDataJobsCommandPattern() {
     return dataJobsCommandPattern;
   }
 
+  public boolean isApmTracingEnabled() {
+    return !appSecStandaloneEnabled && apmTracingEnabled;
+  }
+
   /** @return A map of tags to be applied only to the local application root span. */
   public Map<String, Object> getLocalRootSpanTags() {
     final Map<String, String> runtimeTags = getRuntimeTags();
@@ -3372,7 +3380,7 @@ public Map<String, Object> getLocalRootSpanTags() {
     result.put(LANGUAGE_TAG_KEY, LANGUAGE_TAG_VALUE);
     result.put(SCHEMA_VERSION_TAG_KEY, SpanNaming.instance().version());
     result.put(PROFILING_ENABLED, isProfilingEnabled() ? 1 : 0);
-    if (isAppSecStandaloneEnabled()) {
+    if (!isApmTracingEnabled()) {
       result.put(APM_ENABLED, 0);
     }
 
@@ -3882,10 +3890,6 @@ public Boolean getAppSecScaEnabled() {
     return appSecScaEnabled;
   }
 
-  public boolean isAppSecStandaloneEnabled() {
-    return appSecStandaloneEnabled;
-  }
-
   public boolean isAppSecRaspEnabled() {
     return appSecRaspEnabled;
   }

internal-api/src/main/java/datadog/trace/api/sampling/SamplingMechanism.java

@@ -69,7 +69,7 @@ public static boolean validateWithSamplingPriority(int mechanism, int priority)
    * @return
    */
   public static boolean canAvoidSamplingPriorityLock(int priority, int mechanism) {
-    return Config.get().isAppSecStandaloneEnabled() && mechanism == SamplingMechanism.APPSEC;
+    return !Config.get().isApmTracingEnabled() && mechanism == SamplingMechanism.APPSEC;
   }
 
   private SamplingMechanism() {}