SER2540BU vsphere HA: Leverage Its Full Potential Roman Konarev Aalap Desai #VMworld #SER2540BU
Disclaimer This presentation may contain product features that are currently under development. This overview of new technology represents no commitment from VMware to deliver these features in any generally available product. Features are subject to change, and must not be included in contracts, purchase orders, or sales agreements of any kind. Technical feasibility and market demand will affect final delivery. Pricing and packaging for any new technologies or features discussed or presented have not been determined. 2
Agenda 1 Overview 2 HA in Action: Use Cases and Best Practices 3 Quick Survey 4 Q&A 3
Speakers Aalap Desai Sr Member of Technical Staff Roman Konarev Product Manager 4
Overview
vsphere High Availability Overview: Basics Operates within vcenter Cluster of ESXi hosts Heartbeats via network and storage to communicate availability Networks used by HA: Management network (or) vsan network (only if vsan is enabled) VM 6
vsphere High Availability Overview: Benefits Minimizes unplanned downtime Provides automatic VM recovery in minutes Protects VM against three types of failures Infrastructure (Host and Storage) Connectivity (Network and Storage) Application (Guest OS and Applications/Services) Easy to configure OS and Application independent 7
HA in Action Use Cases and Best Practices
Managing Failovers for Multi-Tier Applications with Orchestrated Restart The goal: Multi-Tier App dependencies are honored during recovery Example: Application: DB server 1 VM; Web Server - 1 VM Capabilities: Orchestrated Restart DB Web 9
Restart Tiers Soft dependency through Five Levels of Restart Tiers Highest High Medium Low Lowest Hard dependency through VM/Host groups 10
Restart Order Model 11
Orchestrated Restart: Configuration 1. Set cluster level default restart priority for VMs 2. Set cluster level default VM Dependency Restart Condition 3. (Decision) Define dependencies across VMs 4. Create associated VM/Host groups 5. Add VMs to the respective VM/Host groups 6. Define the dependencies across VM/Host groups via VM/Host rules 7. (Optional) Define VM overrides for VM s restart priorities (Restart Tiers) Orchestrated Restart will automatically take care of the restart order! 12
1- Set Default VM Restart Priority 13
2 - Set VM Dependency Restart Condition Resources allocated: Once resources for a VM are set aside on the host, HA will move to the next VM. Powered On: Occurs when the power-on command is sent to the VM. Does not wait for the VM s guest OS to be running. Guest Heartbeats detected: Requires VMware Tools. Once vsphere sees that the VMware Tools agent is running, it will proceed. App Heartbeats detected: Requires scripting with the Application Monitoring SDK, however this setting allows for information of a process/application within the VM s guest OS to be shared to notify when an application is up and running in the VM. 14
2 - Set VM Dependency Restart Condition: Best Practices I want to make sure that the resources are allocated for the VM(s) the VM(s) power on successfully the guest OS boots up successfully the application starts up successfully Resources allocated VMworld 2017 Powered On Guest Heartbeats detected App Heartbeats detected Content: Not for publication 15
4 & 5 - Create Associated VM/Host Groups 16
6 - Define Dependencies Across VM/Host Groups 17
7 - (Optional) Define VM Overrides for VM s Restart Priorities 18
Managing Failovers for Multi-Tier Applications with Orchestrated Restart: Notes VM B is dependent on VM A (B->A): if A fails over, the feature does NOT restart B Only direct dependencies are respected C -> B -> A: If A and C fail, A and C will be restarted in parallel C will not wait for A (to have its readiness condition met) Reset operations for VM and Application monitoring and VMCP (APD Timeout) will not be orchestrated 19
VM and Application Monitoring The goal: Properly handle OS and Application failures Example: OS: Windows 2012 Application: DB Server Capabilities: VM and Application Monitoring 20
VM and Application Monitoring VM Monitoring: HA monitors VMware Tools heartbeats and storage or network IO HA will restart a VM if: HA detects red VMware Tools heartbeats AND HA detects that the VM is not generating any storage or network IO Application Monitoring: Prerequisite: Guest and HA Application Monitoring SDK needs to be installed HA monitors application heartbeats HA will restart a VM if: HA detects red application heartbeats OR HA detects Immediate Reset command from the SDK 21
VM and Application Monitoring: Configuration 22
VM and Application Monitoring: Best Practices Always use the latest VMware Tools Generally recommended Heartbeat monitoring sensitivity: Preset-Low + 24h window Test and adjust for your case! Sensitivity Failure Interval Minimum uptime Maximum per-vm resets For Windows VMs, Guest OS crash is detected automatically by VM Monitoring Advanced parameter: das.waitfordumpongoscrash If true (default), HA resets a VM only after the Core Dump is collected Maximum resets time window Low 120 secs 480 secs 3 7 days Medium 60 secs 240 secs 3 24 hrs High 30 secs 120 secs 3 1 hr Set to false if you want HA to immediately reset a VM and not wait for the Core Dump 23
Leverage HA on vsan The goal: Provide High Availability for VMs running on vsan Example: Cluster of hosts with a vsan Datastore and vsan Network Capabilities: All VMworld 2017 Content: Not for publication 24
Leverage HA on vsan: Guidelines No vsan Note: Enable vsan before turning on HA. vsan HA Network Management network Only vsan network Heartbeat Datastore Host Isolation Any traditional Datastore mounted by >1 host Can t ping isolation addresses AND management network is inaccessible Any traditional Datastore mounted by >1 host (no vsan Datastore) Can t ping isolation addresses AND vsan network is inaccessible 25
Leverage HA on vsan: Best Practices Heartbeat Datastores Add a non-vsan Heartbeat Datastore to HA cluster to prevent VM MAC address collisions on the VM network Without Heartbeat Datastores: HA will restart partitioned VMs, resulting in two copies of each VM on each side of the partition. Choose a Heartbeat Datastore that is fault isolated from vsan network. 26
Leverage HA on vsan: Best Practices Host Isolation Use the default gateways of the vsan network as isolation addresses To avoid using the default management network gateway, set the advanced HA option das.usedefaultisolationaddress = false Set isolation addresses via HA advanced option das.isolationaddressx, where X = 0-9 If isolations and partitions are possible, ensure one set of isolation addresses is accessible during a partition. 27
Survey Improving HA Together
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Q & A
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