Minimizing number of synchs

The system of claim 17, wherein the set of synchronization data comprises a first vector of sequence numbers, and wherein the operations further comprise:

• retrieving, by a messaging application, a second vector of sequence numbers;
• and
• identifying one or more sequence numbers that differ between the first and second vectors;
• transmitting the request for content corresponding to the one or more sequence numbers that differ between the first and second vectors.

A system comprising:

• a processor configured to perform operations comprising:
• after ending a synchronization session between a client device and a server receiving, by the client device, content from an out-of-band source;
• after receiving the content from the out-of-band source, receiving, from the server by one or more processors of the client device, a set of synchronization data representing changes since a previous time the client device synchronized with the server;
• generating a local state of synchronization data based on the content received from the out-of-band source;
• comparing, by the one or more processors of the client device, the set of synchronization data to the local state of the synchronization data;
• identifying a difference between the set of synchronization data and the local state of the synchronization data;
• and
• transmitting, to the server by the one or more processors of the client device, a request for content corresponding to the difference between the set of synchronization data and the local state of the synchronization data.

A non-transitory machine-readable storage medium that includes instructions that, when executed by one or more processors of a machine, cause the machine to perform operations comprising:

• after ending a synchronization session between a client device and a server, receiving, by the client device, content from an out-of-band source;
• after receiving the content from the out-of-band source, receiving;
• from the server by one or more processors of the client device, a set of synchronization data representing changes since a previous time the client device synchronized with the server;
• generating a local state of synchronization data based on the content received from the out-of-band source;
• comparing, by the one or more processors of the client device, the set of synchronization data to the local state of the synchronization data;
• identifying a difference between the set of synchronization data and the local state of the synchronization data;
• and
• transmitting, to the server by the one or more processors of the client device, a request for content corresponding to the difference between the set of synchronization data and the local state of the synchronization data.