(accumulo) branch main updated: Fixes ScanTracingIT flaking (#6293)

[kturner]

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kturner pushed a commit to branch main
in repository https://gitbox.apache.org/repos/asf/accumulo.git


The following commit(s) were added to refs/heads/main by this push:
     new 5df8f5d8f9 Fixes ScanTracingIT flaking (#6293)
5df8f5d8f9 is described below

commit 5df8f5d8f9debd24fec3a1924043f54ef3d60076
Author: Keith Turner <ktur...@apache.org>
AuthorDate: Thu Apr 2 15:25:25 2026 -0700

    Fixes ScanTracingIT flaking (#6293)
    
    ScanTracingIT creates a table, does a first scan, and then a second
    scan. In some cases, the test was looking for second scan to all be in
    cache.  However as we learned in #6156 Caffeine may not always keep
    recently added data in cache.  This was causing the stats to sometime
    report cache misses which would fail the test.  The test is not trying
    to test the cache itself, only the stats.  To work around this added
    some intermediate scans between the first traced scan and second traced
    scan.  These intermediate scans ensure the cache is populated for
    validating trace data.
---
 .../accumulo/test/tracing/ScanTraceClient.java     | 23 ++++++++++++++++++++--
 .../accumulo/test/tracing/ScanTracingIT.java       |  6 ++++++
 2 files changed, 27 insertions(+), 2 deletions(-)

diff --git 
a/test/src/main/java/org/apache/accumulo/test/tracing/ScanTraceClient.java 
b/test/src/main/java/org/apache/accumulo/test/tracing/ScanTraceClient.java
index 2196302fea..5d2f894ba4 100644
--- a/test/src/main/java/org/apache/accumulo/test/tracing/ScanTraceClient.java
+++ b/test/src/main/java/org/apache/accumulo/test/tracing/ScanTraceClient.java
@@ -45,6 +45,7 @@ public class ScanTraceClient {
     String endRow;
     String family;
     String qualifier;
+    String untracedIntermediateScans;
 
     Options() {}
 
@@ -75,6 +76,12 @@ public class ScanTraceClient {
       }
     }
 
+    int getUntracedIntermediateScans() {
+      if (untracedIntermediateScans == null) {
+        return 0;
+      }
+      return Integer.parseInt(untracedIntermediateScans);
+    }
   }
 
   public static class Results {
@@ -104,8 +111,7 @@ public class ScanTraceClient {
 
     Tracer tracer = 
GlobalOpenTelemetry.get().getTracer(ScanTraceClient.class.getName());
     try (var client = Accumulo.newClient().from(clientPropsPath).build()) {
-      long scanCount = 0;
-      long scanSize = 0;
+
       long batchScancount = 0;
       long batchScanSize = 0;
 
@@ -121,6 +127,19 @@ public class ScanTraceClient {
       }
       var traceId1 = span.getSpanContext().getTraceId();
 
+      // These scans are done to ensure cacne is populated. Caffeine can evict 
things that were only
+      // used once.
+      for (int i = 0; i < opts.getUntracedIntermediateScans(); i++) {
+        try (var scanner = client.createScanner(table)) {
+          opts.conigureScanner(scanner);
+          scanner.setBatchSize(10_000);
+          var ignored = scanner.stream().count();
+        }
+      }
+
+      long scanCount = 0;
+      long scanSize = 0;
+
       // start a second trace
       span = tracer.spanBuilder("seq-scan").startSpan();
       try (var scanner = client.createScanner(table); var scope = 
span.makeCurrent()) {
diff --git 
a/test/src/main/java/org/apache/accumulo/test/tracing/ScanTracingIT.java 
b/test/src/main/java/org/apache/accumulo/test/tracing/ScanTracingIT.java
index 6e13179d70..e96f1d9151 100644
--- a/test/src/main/java/org/apache/accumulo/test/tracing/ScanTracingIT.java
+++ b/test/src/main/java/org/apache/accumulo/test/tracing/ScanTracingIT.java
@@ -157,6 +157,12 @@ class ScanTracingIT extends ConfigurableMacBase {
       expectedColumns = 1;
     }
 
+    if (secondScanFitsInCache) {
+      // Do a bunch of scans before the second traced scan to make Caffeine 
keep the data. It can
+      // evict recently added data that is only used a few times.
+      options.untracedIntermediateScans = "" + 30;
+    }
+
     var results = run(options);
     System.out.println(results);