diff --git a/fe/fe-core/src/main/java/org/apache/doris/cloud/catalog/CloudReplica.java b/fe/fe-core/src/main/java/org/apache/doris/cloud/catalog/CloudReplica.java
index 1e109c3350e74a..29a1cf9cd71fac 100644
--- a/fe/fe-core/src/main/java/org/apache/doris/cloud/catalog/CloudReplica.java
+++ b/fe/fe-core/src/main/java/org/apache/doris/cloud/catalog/CloudReplica.java
@@ -114,6 +114,21 @@ private boolean isColocated() {
         return Env.getCurrentColocateIndex().isColocateTableNoLock(tableId);
     }
 
+    private boolean isDecommissioningOrDecommissioned(Backend be) {
+        boolean decommissioning = be.isDecommissioning();
+        boolean decommissioned = be.isDecommissioned();
+        if ((decommissioning || decommissioned) && LOG.isDebugEnabled()) {
+            LOG.debug("backend {} is filtered by decommission state, decommissioning={}, decommissioned={}, "
+                            + "replica info {}",
+                    be.getId(), decommissioning, decommissioned, this);
+        }
+        return decommissioning || decommissioned;
+    }
+
+    private boolean isQueryAvailableAndNotDecommissioning(Backend be) {
+        return be != null && be.isQueryAvailable() && !isDecommissioningOrDecommissioned(be);
+    }
+
     public long getColocatedBeId(String clusterId) throws ComputeGroupException {
         CloudSystemInfoService infoService = ((CloudSystemInfoService) Env.getCurrentSystemInfo());
         List<Backend> bes = infoService.getBackendsByClusterId(clusterId).stream()
@@ -129,7 +144,7 @@ public long getColocatedBeId(String clusterId) throws ComputeGroupException {
         List<Backend> decommissionAvailBes = new ArrayList<>();
         for (Backend be : bes) {
             if (be.isAlive()) {
-                if (be.isDecommissioned()) {
+                if (isDecommissioningOrDecommissioned(be)) {
                     decommissionAvailBes.add(be);
                 } else {
                     availableBes.add(be);
@@ -158,7 +173,7 @@ public long getColocatedBeId(String clusterId) throws ComputeGroupException {
                         .collect(Collectors.toList());
                 long index = getIndexByBeNum(hashCode.asLong() + idx, beAliveOrDeadShort.size());
                 Backend be = beAliveOrDeadShort.get((int) index);
-                if (be.isAlive() && !be.isDecommissioned()) {
+                if (be.isAlive() && !isDecommissioningOrDecommissioned(be)) {
                     return be.getId();
                 }
             }
@@ -279,6 +294,10 @@ private long getBackendIdImpl(String clusterId) throws ComputeGroupException {
             }
 
             List<Long> res = hashReplicaToBes(clusterId, false, Config.cloud_replica_num);
+            if (LOG.isDebugEnabled()) {
+                LOG.debug("rehash multi replica backend, clusterId {}, replica info {}, indexRand {}, hashedBes {}",
+                        clusterId, this, indexRand, res);
+            }
             if (res.size() < indexRand + 1) {
                 if (res.isEmpty()) {
                     return -1;
@@ -292,14 +311,14 @@ private long getBackendIdImpl(String clusterId) throws ComputeGroupException {
 
         // use primaryClusterToBackends, if find be normal
         Backend be = getPrimaryBackend(clusterId, false);
-        if (be != null && be.isQueryAvailable()) {
+        if (isQueryAvailableAndNotDecommissioning(be)) {
             return be.getId();
         }
 
         if (!Config.enable_immediate_be_assign) {
             // use secondaryClusterToBackends, if find be normal
             be = getSecondaryBackend(clusterId);
-            if (be != null && be.isQueryAvailable()) {
+            if (isQueryAvailableAndNotDecommissioning(be)) {
                 return be.getId();
             }
         }
@@ -311,6 +330,12 @@ private long getBackendIdImpl(String clusterId) throws ComputeGroupException {
 
         // be abnormal, rehash it. configure settings to different maps
         long pickBeId = hashReplicaToBe(clusterId, false);
+        if (LOG.isDebugEnabled()) {
+            LOG.debug("rehash replica backend, clusterId {}, pickedBeId {}, immediateAssign {}, replica info {}, "
+                            + "primaryBackend {}, secondaryBackend {}",
+                    clusterId, pickBeId, Config.enable_immediate_be_assign, this, getPrimaryBackend(clusterId, false),
+                    getSecondaryBackend(clusterId));
+        }
         if (Config.enable_immediate_be_assign) {
             updateClusterToPrimaryBe(clusterId, pickBeId);
         } else {
@@ -369,7 +394,7 @@ public long hashReplicaToBe(String clusterId, boolean isBackGround) throws Compu
         List<Backend> decommissionAvailBes = new ArrayList<>();
         for (Backend be : clusterBes) {
             if (be.isQueryAvailable() && !be.isSmoothUpgradeSrc()) {
-                if (be.isDecommissioned()) {
+                if (isDecommissioningOrDecommissioned(be)) {
                     decommissionAvailBes.add(be);
                 } else {
                     availableBes.add(be);
@@ -435,7 +460,7 @@ public List<Long> hashReplicaToBes(String clusterId, boolean isBackGround, int r
             // be core or restart must in heartbeat_interval_second
             if ((be.isAlive() || missTimeMs <= Config.heartbeat_interval_second * 1000L)
                     && !be.isSmoothUpgradeSrc()) {
-                if (be.isDecommissioned()) {
+                if (isDecommissioningOrDecommissioned(be)) {
                     decommissionAvailBes.add(be);
                 } else {
                     availableBes.add(be);