[ML] add version information in case of crash of native ML process (#30674)

This change adds version information in case a native ML process crashes, the version is important for choosing the right symbol files when analyzing the crash. Adding the version combines all necessary information on one line.

relates elastic/ml-cpp#94

x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/job/process/NativeController.java

@@ -22,8 +22,6 @@ import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.concurrent.TimeoutException;
-import java.util.regex.Matcher;
-import java.util.regex.Pattern;
 
 
 /**
@@ -84,20 +82,7 @@ public class NativeController {
     }
 
     public Map<String, Object> getNativeCodeInfo() throws TimeoutException {
-        String copyrightMessage = cppLogHandler.getCppCopyright(CONTROLLER_CONNECT_TIMEOUT);
-        Matcher matcher = Pattern.compile("Version (.+) \\(Build ([^)]+)\\) Copyright ").matcher(copyrightMessage);
-        if (matcher.find()) {
-            Map<String, Object> info = new HashMap<>(2);
-            info.put("version", matcher.group(1));
-            info.put("build_hash", matcher.group(2));
-            return info;
-        } else {
-            // If this happens it probably means someone has changed the format in lib/ver/CBuildInfo.cc
-            // in the machine-learning-cpp repo without changing the pattern above to match
-            String msg = "Unexpected native controller process copyright format: " + copyrightMessage;
-            LOGGER.error(msg);
-            throw new ElasticsearchException(msg);
-        }
+        return cppLogHandler.getNativeCodeInfo(CONTROLLER_CONNECT_TIMEOUT);
     }
 
     public void startProcess(List<String> command) throws IOException {

x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/job/process/logging/CppLogMessageHandler.java

@@ -8,7 +8,7 @@ package org.elasticsearch.xpack.ml.job.process.logging;
 import org.apache.logging.log4j.Level;
 import org.apache.logging.log4j.Logger;
 import org.apache.logging.log4j.message.ParameterizedMessage;
-import org.elasticsearch.common.ParsingException;
+import org.elasticsearch.ElasticsearchException;
 import org.elasticsearch.common.Strings;
 import org.elasticsearch.common.bytes.BytesArray;
 import org.elasticsearch.common.bytes.BytesReference;
@@ -30,10 +30,15 @@ import java.time.Duration;
 import java.time.Instant;
 import java.time.temporal.ChronoUnit;
 import java.util.Deque;
+import java.util.HashMap;
+import java.util.Locale;
+import java.util.Map;
 import java.util.Objects;
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.TimeoutException;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
 
 /**
  * Handle a stream of C++ log messages that arrive via a named pipe in JSON format.
@@ -181,6 +186,26 @@ public class CppLogMessageHandler implements Closeable {
         return cppCopyright;
     }
 
+    /**
+     * Extracts version information from the copyright string which assumes a certain format.
+     */
+    public Map<String, Object> getNativeCodeInfo(Duration timeout) throws TimeoutException {
+        String copyrightMessage = getCppCopyright(timeout);
+        Matcher matcher = Pattern.compile("Version (.+) \\(Build ([^)]+)\\) Copyright ").matcher(copyrightMessage);
+        if (matcher.find()) {
+            Map<String, Object> info = new HashMap<>(2);
+            info.put("version", matcher.group(1));
+            info.put("build_hash", matcher.group(2));
+            return info;
+        } else {
+            // If this happens it probably means someone has changed the format in lib/ver/CBuildInfo.cc
+            // in the ml-cpp repo without changing the pattern above to match
+            String msg = "Unexpected native process copyright format: " + copyrightMessage;
+            LOGGER.error(msg);
+            throw new ElasticsearchException(msg);
+        }
+    }
+
     /**
      * Expected to be called very infrequently.
      */
@@ -281,8 +306,18 @@ public class CppLogMessageHandler implements Closeable {
         } catch (XContentParseException e) {
             String upstreamMessage = "Fatal error: '" + bytesRef.utf8ToString() + "'";
             if (upstreamMessage.contains("bad_alloc")) {
-                upstreamMessage += ", process ran out of memory.";
+                upstreamMessage += ", process ran out of memory";
             }
+
+            // add version information, so it's conveniently next to the crash log
+            upstreamMessage += ", version: ";
+            try {
+                Map<String, Object> versionInfo = getNativeCodeInfo(Duration.ofMillis(10));
+                upstreamMessage += String.format(Locale.ROOT, "%s (build %s)", versionInfo.get("version"), versionInfo.get("build_hash"));
+            } catch (TimeoutException timeoutException) {
+                upstreamMessage += "failed to retrieve";
+            }
+
             storeError(upstreamMessage);
             seenFatalError = true;
         } catch (IOException e) {