GH-2184 KafkaBackOffException logged as ERROR

Fixes #2184

Author: tomazfernandes

spring-kafka/src/main/java/org/springframework/kafka/listener/FailedRecordProcessor.java

@@ -152,10 +152,16 @@ protected RecoveryStrategy getRecoveryStrategy(List<ConsumerRecord<?, ?>> record
 			}
 			catch (Exception ex) {
 				if (records.size() > 0) {
-					this.logger.error(ex, () -> "Recovery of record ("
-							+ KafkaUtils.format(records.get(0)) + ") failed");
-					this.failureTracker.getRetryListeners().forEach(rl ->
-							rl.recoveryFailed(records.get(0), thrownException, ex));
+					if (SeekUtils.isBackoffException(ex)) {
+						this.logger.debug("Recovery of record ("
+								+ KafkaUtils.format(records.get(0)) + ") backed off: " + ex.getMessage());
+					}
+					else {
+						this.logger.error(ex, () -> "Recovery of record ("
+								+ KafkaUtils.format(records.get(0)) + ") failed");
+						this.failureTracker.getRetryListeners().forEach(rl ->
+								rl.recoveryFailed(records.get(0), thrownException, ex));
+					}
 				}
 				return (rec, excep, cont, consumer) -> NEVER_SKIP_PREDICATE.test(rec, excep);
 			}