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Author: tlrx

server/src/main/java/org/elasticsearch/index/engine/ReadOnlyEngine.java

@@ -101,16 +101,17 @@ public ReadOnlyEngine(EngineConfig config, SeqNoStats seqNoStats, TranslogStats
                 this.translogStats = translogStats == null ? new TranslogStats(0, 0, 0, 0, 0) : translogStats;
                 if (seqNoStats == null) {
                     seqNoStats = buildSeqNoStats(lastCommittedSegmentInfos);
-                    // the global checkpoint is not always known and up to date when the engine is created,
-                    // so we only check the max seq no / global checkpoint coherency when the global checkpoint
-                    // is different from the unassigned sequence number value. In addition to that we only execute
-                    // the check if the index the engine belongs to has been created after the refactoring of the
-                    // Close Index API and its TransportVerifyShardBeforeCloseAction that guarantee that all
-                    // operations have been flushed to Lucene.
+                    // During a peer-recovery the global checkpoint is not known and up to date when the engine
+                    // is created, so we only check the max seq no / global checkpoint coherency when the global
+                    // checkpoint is different from the unassigned sequence number value.
+                    // In addition to that we only execute the check if the index the engine belongs to has been
+                    // created after the refactoring of the Close Index API and its TransportVerifyShardBeforeCloseAction
+                    // that guarantee that all operations have been flushed to Lucene.
                     final long globalCheckpoint = engineConfig.getGlobalCheckpointSupplier().getAsLong();
                     if (globalCheckpoint != SequenceNumbers.UNASSIGNED_SEQ_NO
                         && engineConfig.getIndexSettings().getIndexVersionCreated().onOrAfter(Version.V_6_7_0)) {
                         if (seqNoStats.getMaxSeqNo() != globalCheckpoint) {
+                            assert false : "max seq. no. [" + seqNoStats.getMaxSeqNo() + "] does not match [" + globalCheckpoint + "]";
                             throw new IllegalStateException("Maximum sequence number [" + seqNoStats.getMaxSeqNo()
                                 + "] from last commit does not match global checkpoint [" + globalCheckpoint + "]");
                         }