The VMRE
handles the lifecycle, compatibility and logging IO of a managed VM process.
The runtime.Initializer
interface could be implemented to manage local or remote VM processes.
This implementation is consumed by a gRPC server which serves the Runtime
service. The server interacts with the underlying process and allows for the VM
binary to communicate with AvalancheGo.
The subprocess
is currently the only supported Runtime
implementation.
It works by starting the VM's as a subprocess of AvalancheGo by os.Exec
.
VMRegistry
calls the RPC Chain VMFactory
.- Factory Starts an instance of a
VMRE
server that consumes aruntime.Initializer
interface implementation. - The address of this server is passed as a ENV variable
AVALANCHE_VM_RUNTIME_ENGINE_ADDR
viaos.Exec
which starts the VM binary. - The VM uses the address of the
VMRE
server to create a client. - Client sends a
Initialize
RPC informing the server of theProtocol Version
and futureAddress
of the RPC Chain VM server allowing it to perform a validationHandshake
. - After the
Handshake
is complete the RPC Chain VM server is started which serves theChainVM
implementation. - The connection details for the RPC Chain VM server are now used to create an RPC Chain VM client.
ChainManager
uses this VM client to bootstrap the chain powered bySnowman
consensus.- To shutdown the VM
runtime.Stop()
sends aSIGTERM
signal to the VM process.
When runtime is Bootstrapped
handshake success is observed during the Initialize
RPC. Process not found means that the runtime Client in the VM binary could not communicate with the runtime Server on AvalancheGo. This could be the result of networking issues or other error in Serve()
.
failed to register VM {"vmID": "tGas3T58KzdjcJ2iKSyiYsWiqYctRXaPTqBCA11BqEkNg8kPc", "error": "handshake failed: timeout"}
To ensure RPC compatibility the protocol version of AvalancheGo must match the subnet VM. To correct this error update the subnet VM's dependencies to the latest version AvalancheGo.
failed to register VM {"vmID": "tGas3T58KzdjcJ2iKSyiYsWiqYctRXaPTqBCA11BqEkNg8kPc", "error": "handshake failed: protocol version mismatch avalanchego: 19 vm: 18"}