POCC

What is it?

Optimistic Causal Consistency (OCC) is a novel approach of causal consistency described in the paper "Optimistic Causal Consistency for Geo-Replicated Key-Value Stores", presented at ICDCS'17 (http://ieeexplore.ieee.org/document/7980260/).

POCC is an implementation of OCC based on physical clocks.

You can find an extended version of the paper at: https://infoscience.epfl.ch/record/225991/files/SDZ-POCC-infoscience.pdf

Compilation

In order to compile this project's code, you need to install gcc4.8, protobuf-2.6.2, boost-1.63.0 and gtest-1.7.0. The default project and build directories are /pocc and /pocc/build. You can change them by changing the PROJECT and BUILD values in the Makefile. The code is then compiled simply by running twice:

    $make all

Running POCC

In order to run POCC, you need to run the group manager, the server and client programs.

The group manager program can be run with:

    $/pocc/build/group_server_program <Port> <NumPartitions> <NumReplicasPerPartition>

A server program can be run with:

    $/pocc/build/kv_server_program <Causal> <KVServerName> <PublicPort> <PartitionPort> <ReplicationPort> <PartitionId> <ReplicaId> <TotalNumKeys> <Durability: Memory> <GroupServerName> <GroupServerPort> <OptimisticMode> <GSTDerivationMode: tree> <GSTInterval (us)> <UpdatePropagationBatchTime (us)> <ReplicationHeartbeatInterval (us)> <WaitConditionInSetOperation (true/false)> <SpinTime: default 500 (us)> <Delta: default 0 (us)>"

A client program can be run with:

    $/pocc/build/run_experiments <Causal> <RequestDistribution: zipfian/uniform> <RequestDistributionParameter> <ReadRatio> <WriteRatio> <ManagerName> <ManagerPort> <TotalNumItems> <WriteValueSize> <NumOpsPerThread: default 0> <NumThreads> <ServingReplicaId> <ClientServerId> <LatencyOutputFileName> <ReservoirSampling: default false> <ReservoirSamplingLimit> <ExperimentDuration: (ms)> <ClientSessionResetLimit> <EnableClientSessionResetLimit: default false> <NumTxReadItems> <NumTxReadItems> <Locality: default -1> <ThinkTime: default 0 (ms)>\n",

Additionally, you can run an interactive client program with:

    $/pocc/build/interactive_kv_client_program <Causal> <ServerName> <ServerPort>

and provide it with the command, or

    $/pocc/build/interactive_kv_client_program <Causal> <ServerName> <ServerPort> <Command>

where 'Command' can be one of:

• Echo
• Get key
• Set key value
• ShowItem
• ShowState

Licensing

POCC is released under the Apache Licence, Version 2.0.

Please see the LICENSE file.

Contact

• Kristina Spirovska [email protected]
• Diego Didona [email protected]

Contributors

• Kristina Spirovska
• Diego Didona
• Jiaqing Du
• Calin Iorgulescu
• Amitabha Roy
• Sameh Elnikety