`tryGetReply` is unreliable, and since `monitorProxies` expects reply
after long period, the connection to coordinator gets closed due to
idle timeout, only to get reopened again in next loop to make
`openDatabase` request.
When using `getReply` our reliable message queue won't be empty and
connection will stay open.
fix: the clientCount was included clients with unknown protocol versions. This has been changed back to the pre-6.2 behavior where it is just a count of clients with known versions, and now clients with unknown versions are tracked explicitly as its own supported_version section
When a process joins a cluster it fetches the cluster
interface. However, not the whole interface is exposed
to the client. This mechanism relies on the fact that
the serializer keeps the field ordering and doesn't
verify the message before parsing it.
To make this work, we provide a client type with one
member (the ClusterInterface which is exposed to the
client and the server). This client interface has the
same FileIdentifier as the ClusterControllerFullInterface
which has the same first member. This works because
FlatBuffers allows for members to be missing.
When the coordinator changes, we use delayedAsyncVar() to reduce
the frequency for cluster controller to send the updated connectedCoordinatorsNumDelayed
to clients.
This help reduce the cluster controllers workload
A client will always try to connect all coordinators.
This commit let Status track the number of connected coordinators
for each client.
This allows us to do canary in coordinators. For example,
when we switch from non-TLS to TLS, we can switch 1 coordinator
from non-TLS to TLS. This can help check if a client has the ability
to connect through TLS.
We can make the non-TLS to TLS switch for each coordinators
one by one. This avoid the risk of losing connection in the switch.
- NetworkAddress now contains IPAddress object which can be either
IPv4 or IPv6 address. 128bits are used even for IPv4 addresses,
however only 32bits are used when using/serializing IPv4 address.
- ConnectPacket is updated to store IPv6 address. Backward compatible
with old format since the first 32bits of IP address field is used
for serialization of IPv4.
- Mainly updates rest of the code to use IPAddress structure instead
of plain uint32_t.
- IPv6 address/pair ports should be represented as `[ip]:port` as per
convention. This applies to both cluster files and command line
arguments.
- This patch will make FDB listen to multiple addresses given via
command line. Although, we'll still use first address in most places,
this patch starts using vector<NetworkAddress> in Endpoint at some basic
places.
- When sending packets to an endpoint, pick a random network address in
endpoints
- Renames Endpoint::address to Endpoint::addresses since it
now holds a vector of addresses.
Extend `Endpoint` class to take multiple NetworkAddresses instead of
just one. Hence, to talk to an endpoint instead of one IP:PORT, we'll
have multiple IP:PORT pairs.
This patch simply adds the field and makes changes to compile the
codebase. The first element of of `address` field is used everywhere.
Hence the way we talk to remains same with this patch.
NOTE:
Directly accessing the first memeber of Endpoint::address is unsafe
as Endpoint() doesn't enforces non-empty address list. However, since
the correctness test pass for now and are anyway replacing all those
unsafe accesses with ones considering the whole vector, this patch
ignores to access them in safe way.
Evan Tschannen