From 1883afeaa313f69f3f756dccbfbdf2539f1fbcda Mon Sep 17 00:00:00 2001
From: frank <frank.zhang@citrix.com>
Date: Wed, 26 Oct 2011 16:14:57 -0700
Subject: [PATCH] Bug 11522 - New agent manager

add update count into host table in order to make agent status update atomic
---
 core/src/com/cloud/host/HostVO.java           | 14 +++++++++++-
 .../src/com/cloud/host/dao/HostDaoImpl.java   | 22 ++++++++++++-------
 setup/db/create-schema.sql                    |  2 +-
 3 files changed, 28 insertions(+), 10 deletions(-)

diff --git a/core/src/com/cloud/host/HostVO.java b/core/src/com/cloud/host/HostVO.java
index 0121225683b..a87a7ee3faa 100755
--- a/core/src/com/cloud/host/HostVO.java
+++ b/core/src/com/cloud/host/HostVO.java
@@ -134,6 +134,9 @@ public class HostVO implements Host {
 
     @Column(name="hypervisor_version")
     private String hypervisorVersion;
+    
+    @Column(name="update_count", updatable = true, nullable=false)
+    protected long updated;	// This field should be updated everytime the state is updated.  There's no set method in the vo object because it is done with in the dao code.
 
     // This is a delayed load value.  If the value is null,
     // then this field has not been loaded yet.
@@ -705,5 +708,14 @@ public class HostVO implements Host {
     public boolean isInMaintenanceStates() {
         return (getResourceState() == ResourceState.Maintenance || getResourceState() == ResourceState.ErrorInMaintenance
                 || getResourceState() == ResourceState.PrepareForMaintenance);
-    }	
+    }
+    
+    public long getUpdated() {
+    	return updated;
+    }
+    
+	public long incrUpdated() {
+		updated++;
+		return updated;
+	}
 }
diff --git a/server/src/com/cloud/host/dao/HostDaoImpl.java b/server/src/com/cloud/host/dao/HostDaoImpl.java
index c0185052fcd..84ae057e058 100755
--- a/server/src/com/cloud/host/dao/HostDaoImpl.java
+++ b/server/src/com/cloud/host/dao/HostDaoImpl.java
@@ -591,6 +591,7 @@ public class HostDaoImpl extends GenericDaoBase<HostVO, Long> implements HostDao
 		SearchBuilder<HostVO> sb = createSearchBuilder();
 		sb.and("status", sb.entity().getStatus(), SearchCriteria.Op.EQ);
 		sb.and("id", sb.entity().getId(), SearchCriteria.Op.EQ);
+		sb.and("update", sb.entity().getUpdated(), SearchCriteria.Op.EQ);
 		if (newStatus.checkManagementServer()) {
 			sb.and("ping", sb.entity().getLastPinged(), SearchCriteria.Op.EQ);
 			sb.and().op("nullmsid", sb.entity().getManagementServerId(), SearchCriteria.Op.NULL);
@@ -603,11 +604,14 @@ public class HostDaoImpl extends GenericDaoBase<HostVO, Long> implements HostDao
 
 		sc.setParameters("status", oldStatus);
 		sc.setParameters("id", host.getId());
+		sc.setParameters("update", host.getUpdated());
+		long oldUpdateCount = host.getUpdated();
 		if (newStatus.checkManagementServer()) {
 			sc.setParameters("ping", oldPingTime);
 			sc.setParameters("msid", host.getManagementServerId());
 		}
 
+		long newUpdateCount = host.incrUpdated();
 		UpdateBuilder ub = getUpdateBuilder(host);
 		ub.set(host, _statusAttr, newStatus);
 		if (newStatus.updateManagementServer()) {
@@ -636,17 +640,19 @@ public class HostDaoImpl extends GenericDaoBase<HostVO, Long> implements HostDao
 			str.append("; Old=[status=").append(oldStatus.toString()).append(":msid=").append(host.getManagementServerId()).append(":lastpinged=")
 			        .append(oldPingTime).append("]");
 			str.append("; DB=[status=").append(vo.getStatus().toString()).append(":msid=").append(vo.getManagementServerId()).append(":lastpinged=")
-			        .append(vo.getLastPinged()).append("]");
+			        .append(vo.getLastPinged()).append(":old update count=").append(oldUpdateCount).append("]");
 			status_logger.debug(str.toString());
+		} else {
+			StringBuilder msg = new StringBuilder("Agent status update: [");
+			msg.append("hostId = " + host.getId());
+			msg.append("; old status = " + oldStatus);
+			msg.append("; event = " + event);
+			msg.append("; new status = " + newStatus);
+			msg.append("; old update count = " + oldUpdateCount);
+			msg.append("; new update count = " + newUpdateCount + "]");
+			status_logger.debug(msg.toString());
 		}
 		
-		StringBuilder msg = new StringBuilder("Agent status update: [");
-		msg.append("hostId = " + host.getId());
-		msg.append("; old status = " + oldStatus);
-		msg.append("; event = " + event);
-		msg.append("; new status = " + newStatus + "]");
-		status_logger.debug(msg.toString());
-		
 		return result > 0;
 	}
 	
diff --git a/setup/db/create-schema.sql b/setup/db/create-schema.sql
index a909fb8d983..69a9960e5f7 100755
--- a/setup/db/create-schema.sql
+++ b/setup/db/create-schema.sql
@@ -698,7 +698,7 @@ CREATE TABLE  `cloud`.`host` (
   `disconnected` datetime COMMENT 'Time this was disconnected',
   `created` datetime COMMENT 'date the host first signed on',
   `removed` datetime COMMENT 'date removed if not null',
-  `allocation_state` varchar(32) NOT NULL DEFAULT 'Enabled' COMMENT 'Is this host enabled for allocation for new resources',
+  `update_count` bigint unsigned NOT NULL DEFAULT 0 COMMENT 'atomic increase count making status update operation atomical',
   `resource_state` varchar(32) NOT NULL DEFAULT 'Disabled' COMMENT 'Is this host enabled for allocation for new resources',
   PRIMARY KEY  (`id`),
   INDEX `i_host__removed`(`removed`),