Consistency interval marker assisted in-band commands in distributed systems

A system, comprising:

• a plurality of nodes in a distributed computing environment;
• a shared replication target device coupled to the plurality of nodes;
• and
• a consistency interval coordinator coupled to the plurality of nodes and the shared replication target device;
• wherein each of the plurality of nodes is an entity configured to send replicated write requests in a request stream or log stream in a distributed computing environment to a shared replication target device, wherein each replicated write request is associated with a first consistency interval;
• wherein the consistency interval coordinator, in response to a request, from one of the plurality of nodes that is configured to send replicated write requests, for a consistency interval transition from the first consistency interval to a second consistency interval, wherein the consistency interval transition applies to each one of the plurality of nodes, is configured to initiate the consistency interval transition to define a point in time for which data on the shared replication target device is in a consistent state, wherein the data on the shared replication target device is consistent with respect to replicated write requests from each one of the plurality of nodes to the shared replication target device for the first consistency interval;
• and
• wherein at least one of the plurality of nodes is configured to send a command message to the shared replication target device, wherein the command message is associated with the consistency interval transition and specifies a requested action to be performed with respect to said consistent state,
• wherein sending the command message comprises inserting the command message for the consistency interval transition in the request stream or the log stream.

A device, comprising:

• one or more processors;
• and
• a memory coupled to the one or more processors, wherein the memory comprises program instructions executable by the one or more processors to implement a node in a networked computing environment, wherein the node is an entity configured to:
• send replicated write requests in a request stream or log stream to a shared replication target device, wherein each replicated write request is associated with a first consistency interval;
• request a consistency interval transition from the first consistency interval to a second consistency interval,
• wherein the node requesting the consistency interval transition is the node sending the replicated write requests,
• wherein the consistency interval transition defines a point in time for which data on the shared replication target device is in a consistent state,
• wherein the data on the shared replication target device is consistent with respect to replicated write requests from the node to the shared replication target device for the first consistency interval and with respect to other replicated write requests from other nodes to the shared replication target device for the first consistency interval;
• and
• send a command message to the shared replication target device, wherein the command message is associated with the consistency interval transition and specifies a request action to be performed with respect to said consistent state,
• wherein sending the command message comprises inserting the command message for the consistency interval transition in the request stream or the log stream.