Hash Distribution Algorithm

For a hash-based distribution algorithm, the most difficult part is to define what hash function would avoid re-distribution. To reduce entry re-distribution, it is also possible to configure the proxy with the maximum number of distribution "slots" upfront, say 10 slots, then associate multiple slots with each service instance.

S1,S2,S3 --> SVC1
S4,S5,S6 --> SVC2
S7, S8, S7, S10 --> SVC3

When the amount of entries stored on SVC1 exceed some limits, a new service instance is set up (say SVC4), one (or more) slots formerly managed by SVC1 are moved to SVC4 (the content of SVC1 is re-distributed to SVC1 and SVC4) and the proxy configuration is changed accordingly, for instance

S1,S2 --> SVC1
S3 --> SVC4
S4,S5,S6 --> SVC2
S7, S8, S7, S10 --> SVC3

This does not solve the re-distribution problem. However, it is much easier to deal with this issue as the number of entries to be re-distributed is much smaller compared to a configuration where the max number of slots has not been planned upfront.