Ref #34306: fix issues with CSV collector and Micrometer

Author: LEDfan

src/main/java/eu/openanalytics/containerproxy/stat/impl/AbstractDbCollector.java

@@ -34,6 +34,7 @@
 import org.slf4j.LoggerFactory;
 import org.springframework.context.ApplicationEvent;
 import org.springframework.context.event.EventListener;
+import org.springframework.scheduling.annotation.Async;
 import org.springframework.security.core.Authentication;
 
 import javax.inject.Inject;
@@ -48,23 +49,27 @@ public abstract class AbstractDbCollector implements IStatCollector {
     private SpecExpressionResolver specExpressionResolver;
     private final Logger logger = LoggerFactory.getLogger(getClass());
 
+    @Async
     @EventListener
     public void onUserLogoutEvent(UserLogoutEvent event) throws IOException {
         writeToDb(event, event.getTimestamp(), event.getUserId(), "Logout", null, event.getAuthentication());
     }
 
+    @Async
     @EventListener
     public void onUserLoginEvent(UserLoginEvent event) throws IOException {
         writeToDb(event, event.getTimestamp(), event.getUserId(), "Login", null, event.getAuthentication());
     }
 
+    @Async
     @EventListener
     public void onProxyStartEvent(ProxyStartEvent event) throws IOException {
         if (event.isLocalEvent()) {
             writeToDb(event,event.getTimestamp(), event.getUserId(), "ProxyStart", event.getSpecId(), event.getAuthentication());
         }
     }
 
+    @Async
     @EventListener
     public void onProxyStopEvent(ProxyStopEvent event) throws IOException {
         if (event.isLocalEvent()) {

src/main/java/eu/openanalytics/containerproxy/stat/impl/CSVCollector.java

@@ -107,10 +107,11 @@ public void init() throws IOException {
 
         schema = schemaBuilder.build();
         writer = csvMapper.writer(schema).writeValues(fileWriter);
+        schema = schemaBuilder.setUseHeader(false).build(); // don't write header when writer re-starts
     }
 
     @Override
-    protected void writeToDb(ApplicationEvent event, long timestamp, String userId, String type, String data, Authentication authentication) throws IOException {
+    protected synchronized void writeToDb(ApplicationEvent event, long timestamp, String userId, String type, String data, Authentication authentication) {
         try {
             Map<String, String> row = new HashMap<>();
             for (String column : schema.getColumnNames()) {