HPCC-33023 Prevent periodic sinks from collecting if prepare fails

system/jlib/jmetrics.cpp

@@ -393,9 +393,11 @@ PeriodicMetricSink::~PeriodicMetricSink()
 void PeriodicMetricSink::startCollection(MetricsManager *_pManager)
 {
     pManager = _pManager;
-    prepareToStartCollecting();
-    isCollecting = true;
-    collectThread = std::thread(&PeriodicMetricSink::collectionThread, this);
+    if (prepareToStartCollecting())
+    {
+        isCollecting = true;
+        collectThread = std::thread(&PeriodicMetricSink::collectionThread, this);
+    }
 }
 
 

system/jlib/jmetrics.hpp

@@ -333,7 +333,7 @@ class jlib_decl PeriodicMetricSink : public MetricSink
 
 protected:
     explicit PeriodicMetricSink(const char *_name, const char *_type, const IPropertyTree *_pSettingsTree);
-    virtual void prepareToStartCollecting() = 0;
+    virtual bool prepareToStartCollecting() = 0;
     virtual void collectingHasStopped() = 0;
     virtual void doCollection() = 0;
     void collectionThread();

system/metrics/sinks/elastic/elasticSink.cpp

@@ -105,9 +105,9 @@ ElasticMetricSink::ElasticMetricSink(const char *name, const IPropertyTree *pSet
 }
 
 
-void ElasticMetricSink::prepareToStartCollecting()
+bool ElasticMetricSink::prepareToStartCollecting()
 {
-
+    return false;
 }
 
 

system/metrics/sinks/elastic/elasticSink.hpp

@@ -31,7 +31,7 @@ class ELASTICSINK_API ElasticMetricSink : public hpccMetrics::PeriodicMetricSink
     ~ElasticMetricSink() override = default;
 
 protected:
-    virtual void prepareToStartCollecting() override;
+    virtual bool prepareToStartCollecting() override;
     virtual void collectingHasStopped() override;
     virtual void doCollection() override;
 

system/metrics/sinks/file/fileSink.cpp

@@ -34,9 +34,10 @@ FileMetricSink::FileMetricSink(const char *name, const IPropertyTree *pSettingsT
 }
 
 
-void FileMetricSink::prepareToStartCollecting()
+bool FileMetricSink::prepareToStartCollecting()
 {
     fhandle = fopen(fileName.str(), clearFileOnStartCollecting ? "w" : "a");
+    return (fhandle != nullptr);
 }
 
 

system/metrics/sinks/file/fileSink.hpp

@@ -34,7 +34,7 @@ class FILESINK_API FileMetricSink : public PeriodicMetricSink
     ~FileMetricSink() override = default;
 
 protected:
-    virtual void prepareToStartCollecting() override;
+    virtual bool prepareToStartCollecting() override;
     virtual void collectingHasStopped() override;
     void doCollection() override;
     virtual void writeReportHeaderToFile() const;

system/metrics/sinks/log/logSink.hpp

@@ -35,7 +35,7 @@ class LOGSINK_API LogMetricSink : public PeriodicMetricSink
     ~LogMetricSink() override = default;
 
 protected:
-    virtual void prepareToStartCollecting() override {}
+    virtual bool prepareToStartCollecting() override { return true; }
     virtual void collectingHasStopped() override {}
     virtual void doCollection() override;
     void writeLogEntry(const std::shared_ptr<IMetric> &pMetric);

testing/unittests/metrics/PeriodicSinkTests.cpp

@@ -35,10 +35,11 @@ class PeriodicTestSink : public PeriodicMetricSink
     ~PeriodicTestSink() = default;
 
 protected:
-    virtual void prepareToStartCollecting() override
+    virtual bool prepareToStartCollecting() override
     {
         prepareCalled = true;
         numCollections = 0;
+        return true;
     }
 
     virtual void collectingHasStopped() override