Allow same host and port for all gateway receivers

To be Reviewed By:

Authors: Alberto Bustamante

Status: Draft | Discussion | Active | Dropped | Superseded

Superseded by: N/A

Related: N/A

Problem

There is a problem with Geode WAN replication when GW receivers are configured with the same hostname-for-senders and port on all servers. The reason for such a setup is deploying Geode cluster on a Kubernetes cluster where all GW receivers are reachable from the outside world on the same VIP and port. Other kinds of configuration (different hostname and/or different port for each GW receiver) are not cheap from OAM and resources perspective in cloud native environments and also limit some important use-cases (like scaling).

Currently, it is possible to set GW receivers as described, but there are some problems derived from this configuration that must be solved prior to state that this configuration is supported by Geode.

Gw sender failover

The problem experienced is that shutting down one server is stopping replication to this cluster until the server is up again. This is because Geode incorrectly assumes there are no more alive servers when just one of them is down, because since they share hostname-for-senders and port, they are treated as one same server.

Gw sender pings not reaching gw receivers

Gw sender use internally a client pool which sends ping messages to the gw receiver it is connected to. In the receivers, ClientHealthMonitor thread is in charge of handle these ping messages. If no one is received from a given sender, it is considered down and the connection is closed. When configuring all gw receivers with same host and port, ping messages are not reaching all the receivers, so connections are closed.

Anti-Goals

What is outside the scope of what the proposal is trying to solve?

Solution

Gw sender failover

on going

Gw sender pings not reaching gw receivers

on going

Changes and Additions to Public Interfaces

If you are proposing to add or modify public interfaces, those changes should be outlined here in detail.

Performance Impact

Do you anticipate the proposed changes to impact performance in any way? Are there plans to measure and/or mitigate the impact?

Backwards Compatibility and Upgrade Path

Will the regular rolling upgrade process work with these changes?

How do the proposed changes impact backwards-compatibility? Are message or file formats changing?

Is there a need for a deprecation process to provide an upgrade path to users who will need to adjust their applications?

Prior Art

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FAQ

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Errata

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