migration: Usable time statistics without requiring NTP

virDomainGetJobStats is able to report statistics of a completed
migration, however to get usable downtime and total time statistics both
hosts have to keep synchronized time. To provide at least some
estimation of the times even when NTP daemons are not running on both
hosts we can just ignore the time needed to transfer a migration cookie
to the destination host. The result will be also inaccurate but a bit
more predictable. The total/down time will just be at least what we
report.

https://bugzilla.redhat.com/show_bug.cgi?id=1213434

diff --git a/include/libvirt/libvirt-domain.h b/include/libvirt/libvirt-domain.h
index 8a4fe531d2188ed8566700536f07d6ab8c364571..5c0a3822ba89f43f6a2e111cbd334ba0968e6899 100644 (file)
--- a/include/libvirt/libvirt-domain.h
+++ b/include/libvirt/libvirt-domain.h
@@ -2547,6 +2547,16 @@ int virDomainAbortJob(virDomainPtr dom);
  */
 # define VIR_DOMAIN_JOB_TIME_ELAPSED             "time_elapsed"
 
+/**
+ * VIR_DOMAIN_JOB_TIME_ELAPSED_NET:
+ *
+ * virDomainGetJobStats field: time (ms) since the beginning of the
+ * migration job NOT including the time required to transfer control
+ * flow from the source host to the destination host,
+ * as VIR_TYPED_PARAM_ULLONG.
+ */
+# define VIR_DOMAIN_JOB_TIME_ELAPSED_NET         "time_elapsed_net"
+
 /**
  * VIR_DOMAIN_JOB_TIME_REMAINING:
  *
@@ -2561,10 +2571,21 @@ int virDomainAbortJob(virDomainPtr dom);
  * VIR_DOMAIN_JOB_DOWNTIME:
  *
  * virDomainGetJobStats field: downtime (ms) that is expected to happen
- * during migration, as VIR_TYPED_PARAM_ULLONG.
+ * during migration, as VIR_TYPED_PARAM_ULLONG. The real computed downtime
+ * between the time guest CPUs were paused and the time they were resumed
+ * is reported for completed migration.
  */
 # define VIR_DOMAIN_JOB_DOWNTIME                 "downtime"
 
+/**
+ * VIR_DOMAIN_JOB_DOWNTIME_NET:
+ *
+ * virDomainGetJobStats field: real measured downtime (ms) NOT including
+ * the time required to transfer control flow from the source host to the
+ * destination host, as VIR_TYPED_PARAM_ULLONG.
+ */
+# define VIR_DOMAIN_JOB_DOWNTIME_NET             "downtime_net"
+
 /**
  * VIR_DOMAIN_JOB_SETUP_TIME:
  *

diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c
index 616e635ab5de9ab3a2a7ac860e438e646800b9cb..6c480c6daf00f50dc46be3f2ca019b39828527a3 100644 (file)
--- a/src/qemu/qemu_domain.c
+++ b/src/qemu/qemu_domain.c
@@ -288,6 +288,13 @@ qemuDomainJobInfoToParams(qemuDomainJobInfoPtr jobInfo,
                                 jobInfo->timeElapsed) < 0)
         goto error;
 
+    if (jobInfo->timeDeltaSet &&
+        jobInfo->timeElapsed > jobInfo->timeDelta &&
+        virTypedParamsAddULLong(&par, &npar, &maxpar,
+                                VIR_DOMAIN_JOB_TIME_ELAPSED_NET,
+                                jobInfo->timeElapsed - jobInfo->timeDelta) < 0)
+        goto error;
+
     if (jobInfo->type == VIR_DOMAIN_JOB_BOUNDED &&
         virTypedParamsAddULLong(&par, &npar, &maxpar,
                                 VIR_DOMAIN_JOB_TIME_REMAINING,
@@ -300,6 +307,14 @@ qemuDomainJobInfoToParams(qemuDomainJobInfoPtr jobInfo,
                                 status->downtime) < 0)
         goto error;
 
+    if (status->downtime_set &&
+        jobInfo->timeDeltaSet &&
+        status->downtime > jobInfo->timeDelta &&
+        virTypedParamsAddULLong(&par, &npar, &maxpar,
+                                VIR_DOMAIN_JOB_DOWNTIME_NET,
+                                status->downtime - jobInfo->timeDelta) < 0)
+        goto error;
+
     if (status->setup_time_set &&
         virTypedParamsAddULLong(&par, &npar, &maxpar,
                                 VIR_DOMAIN_JOB_SETUP_TIME,

diff --git a/src/qemu/qemu_domain.h b/src/qemu/qemu_domain.h
index 382b5c9d2d257466c0ea2708f3e480371b713869..d550ae38fe6e7a1e785d766f1dcd4200d5d741e9 100644 (file)
--- a/src/qemu/qemu_domain.h
+++ b/src/qemu/qemu_domain.h
@@ -100,9 +100,19 @@ struct _qemuDomainJobInfo {
     virDomainJobType type;
     unsigned long long started; /* When the async job started */
     unsigned long long stopped; /* When the domain's CPUs were stopped */
+    unsigned long long sent; /* When the source sent status info to the
+                                destination (only for migrations). */
+    unsigned long long received; /* When the destination host received status
+                                    info from the source (migrations only). */
     /* Computed values */
     unsigned long long timeElapsed;
     unsigned long long timeRemaining;
+    long long timeDelta; /* delta = sent - received, i.e., the difference
+                            between the source and the destination time plus
+                            the time between the end of Perform phase on the
+                            source and the beginning of Finish phase on the
+                            destination. */
+    bool timeDeltaSet;
     /* Raw values from QEMU */
     qemuMonitorMigrationStatus status;
 };

diff --git a/src/qemu/qemu_migration.c b/src/qemu/qemu_migration.c
index 42d27cb4fc5bc7788c35d55e2616a58a7a903a4a..ec72cfac1f544baf2cba2145514f0569dd36aa05 100644 (file)
--- a/src/qemu/qemu_migration.c
+++ b/src/qemu/qemu_migration.c
@@ -688,6 +688,9 @@ qemuMigrationCookieStatisticsXMLFormat(virBufferPtr buf,
 
     virBufferAsprintf(buf, "<started>%llu</started>\n", jobInfo->started);
     virBufferAsprintf(buf, "<stopped>%llu</stopped>\n", jobInfo->stopped);
+    virBufferAsprintf(buf, "<sent>%llu</sent>\n", jobInfo->sent);
+    if (jobInfo->timeDeltaSet)
+        virBufferAsprintf(buf, "<delta>%lld</delta>\n", jobInfo->timeDelta);
 
     virBufferAsprintf(buf, "<%1$s>%2$llu</%1$s>\n",
                       VIR_DOMAIN_JOB_TIME_ELAPSED,
@@ -1046,11 +1049,15 @@ qemuMigrationCookieStatisticsXMLParse(xmlXPathContextPtr ctxt)
 
     virXPathULongLong("string(./started[1])", ctxt, &jobInfo->started);
     virXPathULongLong("string(./stopped[1])", ctxt, &jobInfo->stopped);
+    virXPathULongLong("string(./sent[1])", ctxt, &jobInfo->sent);
+    if (virXPathLongLong("string(./delta[1])", ctxt, &jobInfo->timeDelta) == 0)
+        jobInfo->timeDeltaSet = true;
 
     virXPathULongLong("string(./" VIR_DOMAIN_JOB_TIME_ELAPSED "[1])",
                       ctxt, &jobInfo->timeElapsed);
     virXPathULongLong("string(./" VIR_DOMAIN_JOB_TIME_REMAINING "[1])",
                       ctxt, &jobInfo->timeRemaining);
+
     if (virXPathULongLong("string(./" VIR_DOMAIN_JOB_DOWNTIME "[1])",
                           ctxt, &status->downtime) == 0)
         status->downtime_set = true;
@@ -3438,18 +3445,9 @@ qemuMigrationConfirmPhase(virQEMUDriverPtr driver,
     /* Update total times with the values sent by the destination daemon */
     if (mig->jobInfo) {
         qemuDomainObjPrivatePtr priv = vm->privateData;
-        if (priv->job.completed) {
-            qemuDomainJobInfoPtr jobInfo = priv->job.completed;
-            if (mig->jobInfo->status.downtime_set) {
-                jobInfo->status.downtime = mig->jobInfo->status.downtime;
-                jobInfo->status.downtime_set = true;
-            }
-            if (mig->jobInfo->timeElapsed)
-                jobInfo->timeElapsed = mig->jobInfo->timeElapsed;
-        } else {
-            priv->job.completed = mig->jobInfo;
-            mig->jobInfo = NULL;
-        }
+        VIR_FREE(priv->job.completed);
+        priv->job.completed = mig->jobInfo;
+        mig->jobInfo = NULL;
     }
 
     if (flags & VIR_MIGRATE_OFFLINE)
@@ -4041,6 +4039,7 @@ qemuMigrationRun(virQEMUDriverPtr driver,
     if (priv->job.completed) {
         qemuDomainJobInfoUpdateTime(priv->job.completed);
         qemuDomainJobInfoUpdateDowntime(priv->job.completed);
+        ignore_value(virTimeMillisNow(&priv->job.completed->sent));
     }
 
     if (priv->job.current->type == VIR_DOMAIN_JOB_UNBOUNDED)
@@ -5164,8 +5163,13 @@ qemuMigrationFinish(virQEMUDriverPtr driver,
         }
 
         if (mig->jobInfo) {
-            priv->job.completed = mig->jobInfo;
+            qemuDomainJobInfoPtr jobInfo = mig->jobInfo;
+            priv->job.completed = jobInfo;
             mig->jobInfo = NULL;
+            if (jobInfo->sent && virTimeMillisNow(&jobInfo->received) == 0) {
+                jobInfo->timeDelta = jobInfo->received - jobInfo->sent;
+                jobInfo->timeDeltaSet = true;
+            }
         }
 
         if (!(flags & VIR_MIGRATE_OFFLINE)) {

diff --git a/tools/virsh-domain.c b/tools/virsh-domain.c
index 4f58f07a6b7fd4afa52eb952d47dbd2a8b7085c8..a1900508b68df6b99b187fc36adc1d69ceb9378f 100644 (file)
--- a/tools/virsh-domain.c
+++ b/tools/virsh-domain.c
@@ -5764,6 +5764,15 @@ cmdDomjobinfo(vshControl *ctl, const vshCmd *cmd)
     }
 
     vshPrint(ctl, "%-17s %-12llu ms\n", _("Time elapsed:"), info.timeElapsed);
+    if ((rc = virTypedParamsGetULLong(params, nparams,
+                                      VIR_DOMAIN_JOB_TIME_ELAPSED_NET,
+                                      &value)) < 0) {
+        goto save_error;
+    } else if (rc) {
+        vshPrint(ctl, "%-17s %-12llu ms\n", _("Time elapsed w/o network:"),
+                 value);
+    }
+
     if (info.type == VIR_DOMAIN_JOB_BOUNDED)
         vshPrint(ctl, "%-17s %-12llu ms\n", _("Time remaining:"),
                  info.timeRemaining);
@@ -5852,6 +5861,13 @@ cmdDomjobinfo(vshControl *ctl, const vshCmd *cmd)
         }
     }
 
+    if ((rc = virTypedParamsGetULLong(params, nparams,
+                                      VIR_DOMAIN_JOB_DOWNTIME_NET,
+                                      &value)) < 0)
+        goto save_error;
+    else if (rc)
+        vshPrint(ctl, "%-17s %-12llu ms\n", _("Downtime w/o network:"), value);
+
     if ((rc = virTypedParamsGetULLong(params, nparams,
                                       VIR_DOMAIN_JOB_SETUP_TIME,
                                       &value)) < 0)