Enhance Solr logging

SolrDocumentConverter
- Log warnings (mapping availble but not attribute) only if DEBUG is enabled.

SolrUpdatePipelet
- Deprecate processAsBunch methods (unused, not applicable via script engine).
- New processResponse method providing enhanced logging of what the pipelet sends to Solr server.
diff --git a/core/org.eclipse.smila.solr/code/src/org/eclipse/smila/solr/update/SolrDocumentConverter.java b/core/org.eclipse.smila.solr/code/src/org/eclipse/smila/solr/update/SolrDocumentConverter.java
index 0ad2eb4..c54c6d6 100755
--- a/core/org.eclipse.smila.solr/code/src/org/eclipse/smila/solr/update/SolrDocumentConverter.java
+++ b/core/org.eclipse.smila.solr/code/src/org/eclipse/smila/solr/update/SolrDocumentConverter.java
@@ -192,7 +192,7 @@
         }
       }
     } else {
-      if (_log.isWarnEnabled()) {
+      if (_log.isDebugEnabled()) {
         final String message =
           String.format("Record does not contain mapping for given key. _recordid=%s, key=%s", id, name);
         _log.warn(message);
diff --git a/core/org.eclipse.smila.solr/code/src/org/eclipse/smila/solr/update/SolrUpdatePipelet.java b/core/org.eclipse.smila.solr/code/src/org/eclipse/smila/solr/update/SolrUpdatePipelet.java
index c269fa6..e509c9c 100755
--- a/core/org.eclipse.smila.solr/code/src/org/eclipse/smila/solr/update/SolrUpdatePipelet.java
+++ b/core/org.eclipse.smila.solr/code/src/org/eclipse/smila/solr/update/SolrUpdatePipelet.java
@@ -110,15 +110,15 @@
           case DELETE_BY_QUERY:
             final String query = params.getDeleteQeuery();
             if (query == null) {
-              throw new ProcessingException("Parameter '" + UpdateParams.DELETE_QUERY
-                + "' is required when using operation DELETE_BY_QUERY");
+              throw new ProcessingException(
+                "Parameter '" + UpdateParams.DELETE_QUERY + "' is required when using operation DELETE_BY_QUERY");
             }
             response = server.deleteByQuery(query, commitWithinMs);
             break;
           default:
             throw new NotImplementedException(operation.toString());
         }
-        handleResponse(response, id);
+        processResponse(response, index, operation.toString(), id);
         results.addResult(id);
       } catch (Exception exception) {
         results.addFailedResult(id, exception);
@@ -126,6 +126,28 @@
     }
   }
 
+  private void processResponse(final UpdateResponse response, final String index, final String operation,
+    final String id) {
+    final int status = response.getStatus();
+    if (status == 0) {
+      if (_log.isInfoEnabled()) {
+        final long duration = response.getElapsedTime();
+        final String message =
+          String.format("Process record on Solr server: _recordid: %s; index: %s; operation: %s; duration: %sms.",
+            id, index, operation, duration);
+        _log.info(message);
+      }
+    } else {
+      if (_log.isErrorEnabled()) {
+        final String message =
+          String.format("Cannot process record on Solr server: _recordid: %s; index: %s; operation: %s; status:%s.",
+            id, index, operation, status);
+        _log.error(message);
+      }
+    }
+  }
+
+  @Deprecated
   private void processAsBunch(final Blackboard blackboard, final String[] ids, final UpdateParams params,
     final ResultCollector results) throws ProcessingException {
     final Map<String, Map<Operation, Collection<String>>> serversAndOperations =
@@ -174,6 +196,7 @@
     }
   }
 
+  @Deprecated
   private Map<String, Map<Operation, Collection<String>>> collectServersAndOperations(final String[] ids,
     final UpdateParams params) {
     final Map<String, Map<Operation, Collection<String>>> servers =
@@ -204,15 +227,15 @@
     return servers;
   }
 
+  @Deprecated
   private int calculateLowestCommitWithinMs(final Collection<String> records, final UpdateParams params) {
     int commitWithinMs = UpdateParams.COMMIT_WITHIN_MS_DEFAULT;
     for (final String id : records) {
       params.setCurrentRecord(id);
       final Integer param = params.getCommitWithinMs(false);
       if (param != null) {
-        commitWithinMs =
-          commitWithinMs == UpdateParams.COMMIT_WITHIN_MS_DEFAULT || commitWithinMs > param ? param
-            : commitWithinMs;
+        commitWithinMs = commitWithinMs == UpdateParams.COMMIT_WITHIN_MS_DEFAULT || commitWithinMs > param ? param
+          : commitWithinMs;
       }
     }
     return commitWithinMs;
@@ -232,6 +255,7 @@
     return document;
   }
 
+  @Deprecated
   private void handleResponse(final UpdateResponse response, final String... id) throws ProcessingException {
     if (SolrUtils.isErrorResponse(response)) {
       final String message = String.format("Error returned by Solr (status=%s).", response.getStatus());