Abstract: A technology is provided for managing maintenance operations in a distributed system. Maintenance operations of a plurality of hosts may be tracked in a service provider environment via a maintenance management service. The plurality of hosts are queried to determine availability of each of the plurality of hosts. A schedule for the maintenance operations of the plurality of hosts may be generated based at least in part on the availability of the plurality of hosts and a policy that manages when hosts are allowed to perform maintenance operations. Instructions from the maintenance management service may be sent to the plurality of hosts to schedule the maintenance operations of the plurality of hosts using the schedule.

Abstract: A socket service may be used to link a peer socket to another peer socket. The peer socket is for communicating data to and from a client device and the other peer socket is for communicating data to and from another client device. If a socket opens and the corresponding peer socket is not yet open then the socket waits for the corresponding peer socket to open. When a client device requests a socket to be opened, the client device requests a particular client-defined function mapping to be associated with the socket. When the socket is opened, the endpoint specified in the client-defined function mapping is invoked. An identifier associated with the client device is sent to the endpoint. If the endpoint returns a socket identifier for another socket, then the socket service links the peer socket to the other peer socket, linking the client device to another client device.

Abstract: A technology is described for distributing a publication message. An example method may include receiving a message at a first device gateway to broadcast to devices subscribed to a broadcast topic. The first device gateway maintains a first subscription table indicating which devices connected to the first device gateway are subscribed to the broadcast topic. The first device gateway distributes the message to the devices indicated in the first subscription table as being subscribed to the broadcast topic. In addition, the first device gateway may distribute the message to a second device gateway which maintains a second subscription table indicating which devices connected to the second device gateway are subscribed to the broadcast topic, and the second device gateway distributes the message to the devices indicated in the second subscription table as being subscribed to the broadcast topic.

Abstract: A socket service may be used to implement client-defined function mappings (e.g., custom protocols) for sockets hosted by the socket service so that when a particular socket is opened for a particular client device, the socket operates according to a particular client-defined function mapping requested by the particular client device. To establish a particular client-defined function mapping, a socket manager may receive request from a user that specifies a particular endpoint (e.g., a client-registered function). When a client device requests a socket to be opened, the client device requests the particular client-defined function mapping to be associated with the socket. When the socket is opened, the endpoint is invoked. The particular client-defined function mapping may also specify one or more receive criteria for data received at the socket. If the one or more receive criteria is met, the endpoint is invoked by sending the data to the endpoint.