Declarative Infrastructure with Cloud Foundry BOSH

Editor's Notes

• #11: Cloud Foundry PaaS
• #12: Of course, the BOSH agent on a VM can only communicate back to the Operations Manager if the VM is there, so let’s talk about what happens when a VM disappears. First thing to understand is that by “disappear” I mean that the BOSH agent is not functional; the VM could be there, but Ops Manager no longer knows what it is up to so for all intents and purposes it’s “gone”. How does Ops Manager know? One of the things that a BOSH agent is responsible for is sending out heartbeat messages and by default it does so every 60 seconds. The OMHM is constantly listening for those heartbeats and when it finds that one is missing it will itself produce and alert and pass that through the list of responders. Just as described above, this could result in emails, pages and operations dashboard alerts, but in this case there is one more responder that kicks in – the “resurector”. The resurector will communicate with the IaaS over which PCF is running and will ask that the failed VM be replaced. Of course it will be replaced with a VM running the appropriate part of the elastic runtime – i.e. a health manager or DEA, etc. That’s right, Operations Manager will restart failed cluster components.
• #13: Of course, the BOSH agent on a VM can only communicate back to the Operations Manager if the VM is there, so let’s talk about what happens when a VM disappears. First thing to understand is that by “disappear” I mean that the BOSH agent is not functional; the VM could be there, but Ops Manager no longer knows what it is up to so for all intents and purposes it’s “gone”. How does Ops Manager know? One of the things that a BOSH agent is responsible for is sending out heartbeat messages and by default it does so every 60 seconds. The OMHM is constantly listening for those heartbeats and when it finds that one is missing it will itself produce and alert and pass that through the list of responders. Just as described above, this could result in emails, pages and operations dashboard alerts, but in this case there is one more responder that kicks in – the “resurector”. The resurector will communicate with the IaaS over which PCF is running and will ask that the failed VM be replaced. Of course it will be replaced with a VM running the appropriate part of the elastic runtime – i.e. a health manager or DEA, etc. That’s right, Operations Manager will restart failed cluster components.
• #14: Of course, the BOSH agent on a VM can only communicate back to the Operations Manager if the VM is there, so let’s talk about what happens when a VM disappears. First thing to understand is that by “disappear” I mean that the BOSH agent is not functional; the VM could be there, but Ops Manager no longer knows what it is up to so for all intents and purposes it’s “gone”. How does Ops Manager know? One of the things that a BOSH agent is responsible for is sending out heartbeat messages and by default it does so every 60 seconds. The OMHM is constantly listening for those heartbeats and when it finds that one is missing it will itself produce and alert and pass that through the list of responders. Just as described above, this could result in emails, pages and operations dashboard alerts, but in this case there is one more responder that kicks in – the “resurector”. The resurector will communicate with the IaaS over which PCF is running and will ask that the failed VM be replaced. Of course it will be replaced with a VM running the appropriate part of the elastic runtime – i.e. a health manager or DEA, etc. That’s right, Operations Manager will restart failed cluster components.