OpenStack High Availability

1. OpenStack High Availability JakubPavlik

2. About me • JakubPavlík • Cloud Platform Engineer • 3 years in Cloud • 2 years in OpenStack

3. High Availability vs. Disaster Recovery • High Availability = fault detection & correction procedures to maximize availability of critical services and applications, often in an automated fashion. • Disaster Recovery = process of preparing for recovery or continuation of technology infrastructure critical to an organization after a natural or human-induced disaster. High Availability ≠ Disaster Recovery!

4. Four types of HA in an OpenStackCloud Service Resiliency QoS Cost Transparency Data Integrity ….. Compute Controller Network Controller Database Message Queue Storage .... Applications OpenStack Control services VMs OpenStack Compute Physical nodes Physical network Physical storage Hypervisor Host OS …. Virtual Machine Virtual Network Virtual Storage VM Mobility … Physical infrastructure

5. Physical Infrastructure

6. tcp cloud VPC Hardware Switch 1 Switch 2 Passthru 1 Passthru 2 Passthru 1 Passthru 2 168 cores 3,46GHz ,336 threads agregation ¼ : 1344 vCPU 2688 GB RAM 28 x 10GE ports 168 cores 2,67GHz ,336 threads agregation ¼ : 1344 vCPU 1792 GB RAM 28 x 10GE ports SAN 1 SAN 2 SAN 1 SAN 2 Controller 1 Controller 2 Controller 1 Controller 2

7. OpenStack Control services

8. OpenStack modules – TCP VPC

9. OpenStack High Availability Concepts • Stateless services • There is no dependency between requests • For example APIs: Nova, Keystone, Glance, Cinder, etc. • Stateful services • An action typically compromises multiple requests • For example: MySQL, RabbitMQ, etc. • Active/Passive • Redundant instances of stateless services are load balanced • For Stateful services a replacement resource can be brought online • Active/Active • Redundant instances of stateless services are load balanced • Stateful services are managed in such a way that services are redundant, and that all instances have and identical state.

10. Corosync, Pacemaker and HAProxy • Corosync • Totem single-ring ordering and membership protocol • UDP and InfiniBand based messaging, quorum, and cluster membership to Pacemaker • Pacemaker • High availability and load balancing stack for the Linux platform. • Interacts with applications through Resource Agents (RA) • HAProxy • Load Balancing and Proxying for HTTP and TCP Applications • Works over multiple connections • Used to load balance API services

11. MySQL Galera • Synchronous multi-master cluster technology for MySQL/InnoDB • MySQL patched for wsrep (Write Set REPlication) • Active/active multi-master topology • Read and write to any cluster node • True parallel replication, in row level • No slave lag or integrity issues

12. Sample OpenStack HA architecture • Stateful • Cinder Volume • Neutron L3, DHCP agents • Ceilometer central agent • RabbitMQ • Stateless • Neutron Server • OpenStack APIs • Apache web server • Nova Scheduler • Cinder Scheduler Neutron agents (Active) Neutron agents (Hot Standby)

13. VMs – Compute nodes

14. VMs HA – two layers • Storage • Shared storage filesystem – file disks (qcow2, vmdk, vhv) • Block storage • Network • Vanilla Neutron L3 agent (OpenVSwitch, Linux Bridge) • Vendor plugins - SDN controller

15. No vSphere Style HA with KVM

16. Non-Shared/Shared Storage filesystem • Shared Storage • Live migration – just RAM memory • Hypervisor Evacuation – The instance will be booted from same disk and data will be preserved • CEPH, Gluster, NFS, Samba, GFS • Non-Shared Storage • Block Live Migration – disk and RAM • Hypervisor Evacuation – the instance will be booted from a new disk, but will preserve the configuration, e.g. id, name, uuid • Standard filesystem EXT4, etc.

17. Block Storage - Cinder • Instance boots from volume • iSCSI/FC direct mapping to instance • Enable Live Migration • Cinder Backends • LVM Driver • Default linuxiSCSI server • Vendor software plugins • Gluster, CEPH, VMware VMDK driver • Vendor storage plugins • EMC VNX, IBM Storwize, Solid Fire, etc.

18. Networking - Vanilla Neutron L3 agent • Problems • Routing on Linux server (max. bandwith approximately 3-4 Gbits) • Limited distribution between more network nodes • East-West and North-South communication through network node • High Availability • Pacemaker&Corosync • Keepalived VRRP • DVR + VRRP – should be in Juno release

19. Networking – Vendor SDN Controller plugins • Examples • Juniper OpenContrail, VMware NSX, SDN PLUMgrid • Advantages against Neutron L3 agent • North-South communication on network devices (iBGP, MLPSoverGRE) • East-West communication directly between compute nodes • Higher bandwidth (9.7 Gbits per 10Gbits port) • High Availability • iBGP peering into two routers • Native HA implemented inside of network devices

20. Contrail Database Contrail Database Contrail Database Openstack Controller Openstack Controller Openstack Controller Zookeeper Zookeeper Zookeeper OpenStack HA TCP VPC VIP Cassandra Cassandra Cassandra GALERA MySQL MySQL MySQL RabbitMQ RabbitMQ RabbitMQ Bond Interface Pacemaker Corosync Pacemaker Corosync HAProxy HAProxy HAProxy Contrail Config with Analytics & WebUI Contrail Config with Analytics & WebUI Contrail Config with Analytics & WebUI Contrail Control Contrail Control

21. TCP Virtual Private Cloud

22. HA methods - vendors

23. Thank you for your attention!