diff --git a/installer/sashimono-uninstall.sh b/installer/sashimono-uninstall.sh
index 3606fcb..69d8c94 100755
--- a/installer/sashimono-uninstall.sh
+++ b/installer/sashimono-uninstall.sh
@@ -155,7 +155,10 @@ if grep -q "^$MB_XRPL_USER:" /etc/passwd; then
     fi
 
     echo "Deleting message board user..."
-    killall -u $MB_XRPL_USER # Kill any running processes.
+    # Killall command is not found in every linux systems, therefore pkill command is used. 
+    # A small timeout(0.1 second) is applied before deleting the user because it takes some time to kill all the processes
+    pkill -u $MB_XRPL_USER # Kill any running processes.
+    sleep 0.1
     userdel -f "$MB_XRPL_USER"
     rm -r /home/"${MB_XRPL_USER:?}"
 
diff --git a/mb-xrpl/lib/message-board.js b/mb-xrpl/lib/message-board.js
index 13e11a5..17530c9 100644
--- a/mb-xrpl/lib/message-board.js
+++ b/mb-xrpl/lib/message-board.js
@@ -73,6 +73,7 @@ class MessageBoard {
         await this.hostClient.updateRegInfo(this.activeInstanceCount, this.cfg.version);
         this.db.close();
 
+        let ongoingHeartbeat = false;
         // Check for instance expiry.
         this.xrplApi.on(evernode.XrplApiEvents.LEDGER, async (e) => {
             this.lastValidatedLedgerIndex = e.ledger_index;
@@ -80,13 +81,14 @@ class MessageBoard {
             const currentMoment = await this.hostClient.getMoment(e.ledger_index);
 
             // Sending heartbeat every CONF_HOST_HEARTBEAT_FREQ moments.
-            if (this.lastHeartbeatMoment === 0 || (currentMoment % this.hostClient.config.hostHeartbeatFreq === 0 && currentMoment !== this.lastHeartbeatMoment)) {
-                this.lastHeartbeatMoment = currentMoment;
-
-                console.log(`Reporting heartbeat at Moment ${this.lastHeartbeatMoment}...`)
+            if ( ! ongoingHeartbeat &&
+                (this.lastHeartbeatMoment === 0 || (currentMoment % this.hostClient.config.hostHeartbeatFreq === 0 && currentMoment !== this.lastHeartbeatMoment))) {
+                ongoingHeartbeat = true;
+                console.log(`Reporting heartbeat at Moment ${this.lastHeartbeatMoment}...`);
 
                 try {
                     await this.hostClient.heartbeat();
+                    this.lastHeartbeatMoment = currentMoment;
                 }
                 catch (err) {
                     if (err.code === 'tecHOOK_REJECTED')
@@ -94,6 +96,9 @@ class MessageBoard {
                     else
                         console.log("Heartbeat tx error", err);
                 }
+                finally {
+                    ongoingHeartbeat = false;
+                }
             }
 
             // Filter out instances which needed to be expired and destroy them.