Merge pull request #190 from sharady/vmss-v2

VM Schedule Snapshot Design changes v2

Author: robhoes

xapi/design/schedule-snapshot.md

@@ -3,8 +3,13 @@ title: Schedule Snapshot Design
 layout: default
 design_doc: true
 design_review: 186
-revision: 1
+revision: 2
 status: proposed
+revision_history:
+- revision_number: 1
+  description: Initial version
+- revision_number: 2
+  description: Renaming VMSS fields and APIs. API message_create superseeds vmss_create_alerts.
 ---
 
 The scheduled snapshot feature will utilize the existing architecture of VMPR. In terms of functionality, schedule snapshot is basically VMPR without its archiving capability.
@@ -13,7 +18,14 @@ Introduction
 ------------
 
 * Schedule snapshot will be a new object in xapi as VMSS.
-* A pool can have multiple VMSS and each VMSS will be configured to take snapshot of type disk, checkpoint or quiesce for the VMs as part of VMSS, on configured intervals.
+* A pool can have multiple VMSS.
+* Multiple VMs can be a part of VMSS but a VM cannot be a part of multiple VMSS.
+* A VMSS takes VMs snapshot with type [`snapshot`, `checkpoint`, `snapshot_with_quiesce`].
+* VMSS takes snapshot of VMs on configured intervals:
+	* `hourly` -> On everyday, Each hour, Mins [0;15;30;45]
+	* `daily` -> On everyday, Hour [0 to 23], Mins [0;15;30;45]
+	* `weekly` -> Days [`Monday`,`Tuesday`,`Wednesday`,`Thursday`,`Friday`,`Saturday`,`Sunday`], Hour[0 to 23], Mins [0;15;30;45]
+* VMSS will have a limit on retaining number of VM snapshots in range [1 to 10].
 
 Datapath Design
 ---------------
@@ -22,7 +34,6 @@ Datapath Design
 * VMSS plugin will go through all the schedule snapshot policies in the pool and check if any of them are due.
 * If a snapshot is due then : Go through all the VM objects in XAPI associated with this schedule snapshot policy and create a new snapshot.
 * If the snapshot operation fails, create a notification alert for the event and move to the next VM.
-* Flag the snapshot to have been created by the schedule service, using either other-config for the VM object or another parameter added for this purpose.
 * Check if an older snapshot now needs to be deleted to comply with the retention value defined in the schedule policy.
 * If we need to delete any existing snapshots, delete the oldest snapshot created via schedule policy.
 * Set the last-run timestamp in the schedule policy.
@@ -34,45 +45,49 @@ There is a new record for VM Scheduled Snapshot with new fields.
 
 New fields:
 
-* "name-label" type String : Name label for VMSS.
-* "name-description" type String : Name description for VMSS.
-* "is-schedule-snapshot-enabled" type Bool : Enable/Disable VMSS to take snapshot.
-* "schedule-snapshot-type" type [DiskSnapshot; Checkpoint; Quiesce] : Type of snapshot policy takes.
-* "schedule-snapshot-retention-value" type Int64 : Number of snapshots limit for a VM, max limit is 10.
-* "schedule-snapshot-frequency" type [hourly; daily; weekly] : Frequency of taking snapshot of VMs.
-* "snapshot-schedule" type (hour: DateTime, min: DateTime, days: string list) : Time Hour, Min of interval  of 15mins and Days of a week. 
-* "is-schedule-snapshot-running" type Bool : If VMSS is in progress of taking snapshot.
-* "schedule-snapshot-last-run-time" type Date : DateTime of last execution of VMSS.
-* "is-alarm-enabled" type Bool : Alarm enable/disable for VMSS.
-* "alarm-config" : type (is_alarm_enabled,["email_address", ((String), "");"smtp_server", ((String), "");"smtp_port", ((IntRange(1,65535)), "25")] : Sets the alarm config field for VMSS.
-* "VMs" type VM refs : List of VMs part of VMSS.
+* `name-label` type `String` : Name label for VMSS.
+* `name-description` type `String` : Name description for VMSS.
+* `enabled` type `Bool` : Enable/Disable VMSS to take snapshot.
+* `type` type `Enum` [`snapshot`; `checkpoint`; `snapshot_with_quiesce`] : Type of snapshot VMSS takes.
+* `retention-value` type `Int64` : Number of snapshots limit for a VM, max limit is 10 and default is 7.
+* `frequency` type `Enum` [`hourly`; `daily`; `weekly`] : Frequency of taking snapshot of VMs.
+* `schedule` type `Map(String,String)` with (key, value) pair:
+	* hour : 0 to 23
+	* min : [0;15;30;45]
+	* days : [`Monday`,`Tuesday`,`Wednesday`,`Thursday`,`Friday`,`Saturday`,`Sunday`]
+* `last-run-time` type Date : DateTime of last execution of VMSS.
+* `is-alarm-enabled` type Bool : Alarm enable/disable for VMSS.
+* `alarm-config` : `Map(String,String)` with (key, value) pair:
+	* email_address : ((String), "")
+	* smtp_server : ((String), "")
+	* smtp_port : ((IntRange(1,65535)), "25")
+Sets the alarm config field for VMSS.
+* `VMs` type VM refs : List of VMs part of VMSS.
 
 New fields to VM record:
 
-* "schedule-snapshot" type VMSS ref : VM part of VMSS.
-* "is-snapshot-from-vmss" type Bool : If snapshot created from VMSS.
+* `schedule-snapshot` type VMSS ref : VM part of VMSS.
+* `is-vmss-snapshot` type Bool : If snapshot created from VMSS.
 
 New APIs
 --------
 
 * vmss_snapshot_now (Ref vmss, Pool_Operater) -> String : This call executes the schedule snapshot immediately.
-* vmss_create_alert (Ref _vmss, String "name", Int "priority", String "body", String "data", Local_Root) -> unit : This call creates an alert for schedule snapshot.
-* vmss_get_alerts (Ref vmss, Int "hours_from_now", Pool_Operater) -> Set String : This call fetches a history of alerts for a given schedule snapshot
-* vmss_set_snapshot_retention_value (Ref vmss, Int value, Pool_Operater) -> unit : Set the value of the_schedule_snapshot_retention value max is 10.
-* vmss_set_is_schedule_snapshot_running (Ref vmss, Bool value, Local_Root) -> unit : Set the value of the is_schedule_snapshot_running field
-* vmss_set_snapshot_frequency (Ref vmss, String "value", Pool_Operater) -> unit : Set the value of the snapshot_frequency field
-* vmss_set_snapshot_schedule (Ref vmss, Map(String,String) "value", Pool_Operater) -> unit : Set the schedule to take snapshot.
-* vmss_set_is_alarm_enabled (Ref vmss, Bool "value", Pool_Operater) -> unit : Set the value of the is_alarm_enabled field
-* vmss_set_alarm_config (Ref vmss, Map(String,String) "value", Pool_Operater) -> unit : Set the alarm_config
-* vmss_add_to_snapshot_schedule (Ref vmss, String "key", String "value", Pool_Operater) -> unit : Add key value pair to VMSS
-* vmss_add_to_alarm_config (Ref vmss, String "key", String "value", Pool_Operater) -> unit : Add key value pair to alarm_config field.
-* vmss_remove_from_snapshot_schedule (Ref vmss, String "key", Pool_Operater) -> unit : Remove key from VMSS.
-* vmss_remove_from_alarm_config (Ref vmss, String "key", Pool_Operater) -> unit : Remove key from alarm_config field.
-* vmss_set_schedule_snapshot_last_run_time (Ref vmss, DateTime "value", Local_Root) -> unit : Set the last run time for VMSS.
+* vmss_get_alerts (Ref vmss, Int "hours_from_now", Pool_Operater) -> Set String : This call fetches a history of alerts for a given schedule snapshot.
+* vmss_set_retention_value (Ref vmss, Int value, Pool_Operater) -> unit : Set the value of vmss retention value, max is 10.
+* vmss_set_frequency (Ref vmss, String "value", Pool_Operater) -> unit : Set the value of the vmss frequency field.
+* vmss_set_type (Ref vmss, String "value", Pool_Operater) -> unit : Set the snapshot type of the vmss type field.
+* vmss_set_schedule (Ref vmss, Map(String,String) "value", Pool_Operater) -> unit : Set the vmss schedule to take snapshot.
+* vmss_set_is_alarm_enabled (Ref vmss, Bool "value", Pool_Operater) -> unit : Set the value of the is_alarm_enabled field.
+* vmss_set_alarm_config (Ref vmss, Map(String,String) "value", Pool_Operater) -> unit : Set the alarm_config.
+* vmss_add_to_schedule (Ref vmss, String "key", String "value", Pool_Operater) -> unit : Add key value pair to VMSS schedule.
+* vmss_add_to_alarm_config (Ref vmss, String "key", String "value", Pool_Operater) -> unit : Add key value pair to VMSS alarm_config field.
+* vmss_remove_from_schedule (Ref vmss, String "key", Pool_Operater) -> unit : Remove key from VMSS schedule.
+* vmss_remove_from_alarm_config (Ref vmss, String "key", Pool_Operater) -> unit : Remove key from VMSS alarm_config field.
+* vmss_set_last_run_time (Ref vmss, DateTime "value", Local_Root) -> unit : Set the last run time for VMSS.
 
 New CLIs
 --------
 
-* vmss-create (required : "name-label";"schedule-snapshot-type";"schedule-snapshot-frequency", optional : "name-description";"is-schedule-snapshot-enabled";"snapshot-schedule:";"snapshot-retention-value";"is-alarm-enabled";"alarm-config:") -> unit : Creates VM schedule snapshot.
+* vmss-create (required : "name-label";"type";"frequency", optional : "name-description";"is-enabled";"schedule:";"retention-value";"is-alarm-enabled";"alarm-config:") -> unit : Creates VM schedule snapshot.
 * vmss-destroy (required : uuid) -> unit : Destroys a VM schedule snapshot.
-