Explain how chord works. To increasing the fault tolerance in chord, each node maintains a successor list (finger table) instead of a single successor. Explain the lookup algorithm for finding an object in this structure.

Chord is a set of rules for a peer-to-peer distributed hash table it collects key-value sets by allotting keys to several computers (known as "nodes"); a node will collect the values for all the keys for which that is reliable. Chord defines how keys are allocated to the nodes, and how a node can determine the value for a distributed key by first locating the node liable for such key.

Explanation:

A chord is a peer-to-peer lookup service. It Resolves the difficulty of establishing a data item in a combination of shared nodes, considering various node arrivals and removals The most crucial operation in most peer-to-peer method is the efficient position of data objects.

It is able of supporting only one operation i.e. given a key, it maps the key on a link.

Algorithm:

Algorithm shows working of the chord:

// x is a node used to find successor of id

x.find_successor(id)

if (id (x; successor])

return successor;

else

// query is being delivered around the circle

entrance successor.find_successor(id);