Carlos Eduardo Benevides Bezerra

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In a distributed MMOG (massively multiplayer online game) server architecture , the server nodes may become easily overloaded by the high demand from the players for state updates. Many works propose algorithms to distribute the load on the server nodes, but this load is usually defined as the number of players on each server, what is not an ideal measure.(More)
State-machine replication, a fundamental approach to designing fault-tolerant services, requires commands to be executed in the same order by all replicas. Moreover, command execution must be deterministic: each replica must produce the same output upon executing the same sequence of commands. These requirements usually result in single-threaded replicas,(More)
Traditionally, a central server is utilized to provide support to MMOGs (massively multiplayer online games), where the number of participants is in the order of tens of thousands. Much work has been done trying to create a fully peer-to-peer model to support this kind of application, in order to minimize the maintenance cost of its infrastructure, but(More)
State machine replication (SMR) is a well-known technique able to provide fault-tolerance. SMR consists of sequencing client requests and executing them against replicas in the same order, thanks to deterministic execution, every replica will reach the same state after the execution of each request. However, SMR is not scalable since any replica added to(More)
In massively multiplayer online games (MMOGs) there is a great demand for high bandwidth connections with irregular access patterns. Such irregular demand is because players, who can vary from a few hundred to several tens of thousands, often occupy the virtual environment of the game in different ways with varying densities. Hence there is a great need for(More)
State machine replication (SMR) is a well-known technique that guarantees strong consistency (i.e., linearizability) to online services. In SMR, client commands are executed in the same order on all server replicas: after executing each command, every replica reaches the same state. However, SMR lacks scalability: every replica executes all commands, so(More)
Message ordering is one of the cornerstones of reliable distributed systems. However, some ordering guarantees, such as atomic order, are expensive to implement in terms of message delays. This paper presents Optimistic Atomic Multicast, a protocol that combines reduced latency and increased throughput. Messages can be delivered optimistically in a single(More)
MMOGs (massively multiplayer online games) are applications that require high bandwidth connections to work properly. This demand for bandwidth is specially critical on the servers that host the game. This happens because the typical number of simultaneous participants in this kind of game varies from a few hundreds to several tens of thousands, and the(More)
Today's online services must meet strict availability and performance requirements. State machine repli-cation, one of the most fundamental approaches to increasing the availability of services without sacrificing strong consistency, provides configurable availability but limited performance scalability. Scal-able State Machine Replication (S-SMR) achieves(More)