From 69f7b4d1f75569bc540a880dc5c3d9e7c8028e03 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Pavel=20Czern=C3=BD?= <pczerny@opennebula.systems>
Date: Wed, 12 May 2021 11:21:27 +0200
Subject: [PATCH] B #5289: Better update of sched_message (#1205)

Updating whole user_template may cause lost of data due to race
conditions. It's better to send update only for modified attribute, in
this case only SCHED_MESSAGE
---
 src/scheduler/include/VirtualMachineXML.h     |  7 ++++
 .../src/pool/VirtualMachinePoolXML.cc         |  9 +++--
 src/scheduler/src/pool/VirtualMachineXML.cc   | 34 ++++++++++++++++++-
 src/scheduler/src/sched/Scheduler.cc          | 10 ------
 4 files changed, 44 insertions(+), 16 deletions(-)

diff --git a/src/scheduler/include/VirtualMachineXML.h b/src/scheduler/include/VirtualMachineXML.h
index 31bd08d279..68920d696e 100644
--- a/src/scheduler/include/VirtualMachineXML.h
+++ b/src/scheduler/include/VirtualMachineXML.h
@@ -457,6 +457,13 @@ protected:
 
     void init_storage_usage();
 
+    /**
+     * Update the VM object in oned
+     * @param vm_template Object template as xml or ...
+     * @param append Append mode
+     */
+    bool update(const std::string &vm_template, bool append);
+
     /* ---------------------- SCHEDULER INFORMATION ------------------------- */
     ResourceMatch match_hosts;
 
diff --git a/src/scheduler/src/pool/VirtualMachinePoolXML.cc b/src/scheduler/src/pool/VirtualMachinePoolXML.cc
index 13ea1e8054..7b378f0b2f 100644
--- a/src/scheduler/src/pool/VirtualMachinePoolXML.cc
+++ b/src/scheduler/src/pool/VirtualMachinePoolXML.cc
@@ -238,15 +238,14 @@ int VirtualMachinePoolXML::load_info(xmlrpc_c::value &result)
 /* -------------------------------------------------------------------------- */
 /* -------------------------------------------------------------------------- */
 
-int VirtualMachinePoolXML::dispatch(int vid, int hid, int dsid, bool resched,const string& extra_template) const
+int VirtualMachinePoolXML::dispatch(int vid, int hid, int dsid, bool resched,
+                                    const string& extra_template) const
 {
     xmlrpc_c::value deploy_result;
 
-    VirtualMachineXML* vm = get(vid);
-
-    if (vm != 0 && vm->clear_log())
+    if (auto vm = get(vid))
     {
-        update(vm);
+        vm->clear_log();
     }
 
     try
diff --git a/src/scheduler/src/pool/VirtualMachineXML.cc b/src/scheduler/src/pool/VirtualMachineXML.cc
index a0c5195c4f..01931d3dbd 100644
--- a/src/scheduler/src/pool/VirtualMachineXML.cc
+++ b/src/scheduler/src/pool/VirtualMachineXML.cc
@@ -607,7 +607,14 @@ void VirtualMachineXML::log(const string &st)
 
     oss << one_util::log_time() << ": " << st;
 
-    user_template->replace("SCHED_MESSAGE", oss.str());
+    string sched_message = oss.str();
+
+    user_template->replace("SCHED_MESSAGE", sched_message);
+
+    oss.str("");
+    oss << "SCHED_MESSAGE = \"" << sched_message << "\"";
+
+    update(oss.str(), true);    // Send the update to oned
 }
 
 /* -------------------------------------------------------------------------- */
@@ -631,6 +638,8 @@ bool VirtualMachineXML::clear_log()
 
     user_template->erase("SCHED_MESSAGE");
 
+    update("SCHED_MESSAGE = \"\"", true);   // Send update to oned
+
     return true;
 }
 
@@ -672,3 +681,26 @@ int VirtualMachineXML::parse_action_name(string& action_st)
     return 0;
 };
 
+/* -------------------------------------------------------------------------- */
+/* -------------------------------------------------------------------------- */
+
+bool VirtualMachineXML::update(const string &vm_template, bool append)
+{
+    xmlrpc_c::value result;
+
+    try
+    {
+        Client::client()->call("one.vm.update", "isi", &result, oid,
+                               vm_template.c_str(),
+                               append ? 1 : 0);
+    }
+    catch (exception const& e)
+    {
+        return false;
+    }
+
+    vector<xmlrpc_c::value> values =
+            xmlrpc_c::value_array(result).vectorValueValue();
+
+    return xmlrpc_c::value_boolean(values[0]);
+}
diff --git a/src/scheduler/src/sched/Scheduler.cc b/src/scheduler/src/sched/Scheduler.cc
index d1e97534dd..0b813b2d4b 100644
--- a/src/scheduler/src/sched/Scheduler.cc
+++ b/src/scheduler/src/sched/Scheduler.cc
@@ -895,7 +895,6 @@ void Scheduler::match_schedule()
                     log_match(vm->get_oid(), "Cannot schedule VM. "+ m_error);
 
                     vm->log("Cannot schedule VM. "+ m_error);
-                    vmpool->update(vm);
 
                     continue;
                 }
@@ -973,8 +972,6 @@ void Scheduler::match_schedule()
                 }
             }
 
-            vmpool->update(vm);
-
             log_match(vm->get_oid(),
                     "Cannot schedule VM, there is no suitable host.");
 
@@ -1090,8 +1087,6 @@ void Scheduler::match_schedule()
 
                 vm->clear_match_hosts();
 
-                vmpool->update(vm);
-
                 log_match(vm->get_oid(), "Cannot schedule VM, there is no suitable "
                     "system ds.");
 
@@ -1194,8 +1189,6 @@ void Scheduler::match_schedule()
                 vm->clear_match_hosts();
                 vm->clear_match_datastores();
 
-                vmpool->update(vm);
-
                 log_match(vm->get_oid(), "Cannot schedule VM, there is no "
                     "suitable network.");
 
@@ -1339,8 +1332,6 @@ void Scheduler::dispatch()
                 {
                     vm->log("Cannot dispatch VM. " + error);
 
-                    vmpool->update(vm);
-
                     continue;
                 }
             }
@@ -1664,7 +1655,6 @@ void Scheduler::dispatch()
             vm->log("Cannot dispatch VM to any Host. Possible reasons: Not "
                 "enough capacity in Host or System DS, dispatch limit "
                 "reached, or limit of free leases reached.");
-            vmpool->update(vm);
         }
     }