Paxos is a family of protocols for a network of unreliable processors to agree on a result.
Questions tagged [paxos]
132 questions
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What is a "view" in the Paxos consensus algorithm?
I have pasted pseudocode for a paxos algorithm below and was wondering if someone could point me in the right direction. I am trying to implement the algorithm below, but I'm a confused what exactly "views" represents below. I know the comment…
user1068636
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Cassandra LWT CasWriteUnknownResultException failure status is unclear
When executing a LWT such as INSERT .... IF NOT EXISTS, the Java driver may throw a CASWriteUnknownException. It's unclear (a) what phase failed (b) if the LWT transaction has completely failed or was partially successful and caused a mutation and…
Brad Schoening
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How Raft know previous term log entry committed or not
When I study raft, I have a problem.
A Raft cluster has 5 servers. we call them a,b,c,d,e. a is the leader. Now everything is ok.
Then, A handle a client request, makes a log entry.
scenario 1,
b & c replicate the log entry, d & e don't.
Then a &…
tlb
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Paxos: What happens if the leader lost connection after commit in his own ledger but before multicast the success message?
From the The Part-Time Parliament essay, what happens with the following situation.
The leader receives Voted(b, q) message from the majority and writes this degree
in his own ledger, but lost connection before sending the Success(d) message.
with…
newbee
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How does raft prevent submitted logs from being overwritten
figure 8 in raft paper
Consider a situation like the figure 8 in raft paper, but in (c), log entry from term 2 has been commited, and s1 crashs, s5 becomes leader, then s5 send append entry rpc to s2, s3, s4, according to the rule, s2, s3, s4 must…
zelin
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what is the key difference between multipaxos and basic paxos protocol
how is multipaxos different from basic paxos? How does ordering work in multipaxos?
Can someone explain multi-paxos along with the diagram
Tried out going through videos and research papers but cannot understand the exact difference and concept of…
anonymousM
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How doesn't Hbase use any consensus algorithm like RAFT or Paxos?
I know replication in HBase is done via append only log files, to maintain the same order of entries as that in master to get replicated to slave's WALs I assume there must be some consensus protocol. How is it designed so that there isn't any…
Yaswanth Tavva
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Multiple Consensus in Simple Paxos
How does a group have multiple consensus at different point of time. Let me try to explain the question with an example. Let us assume that there 10 process, among them 3 are proposers(P0, P1, P2). A Paxos round concludes and every body agrees on…
user3038038
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distributed system (RPC + Paxos)
I want to ensure consistency between 3 servers.
It's a consensus problem.
Each server listens to the users and saves the collected data in a local file.
I tried to use Rpc to send the new data to all the others servers but in vain.
Also I want to…
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Can multiple values be accepted in a single run?
Consider the following flow :
Proposer prepares a message, gets a promise, sends a proposal with some value, gets it accepted. All fine.
After acceptance, another proposer comes along and prepares a message with a higer id, and the same flow…
nz_21
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How can I understand "value" in bacis paxos
I am reading Lamport's Paxos Mode Simple, and I get confused with the meaning "value" here.
For example, Lamport says:
If a proposal with value v is chosen, then every higher-numbered proposal that is chosen has value v
I don't know what value v…
calvin
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Two Phase Commit blocking on coordinator failure
I was trying to read the Paxos Commit paper and am struggling witih moving past the introduction. The intial section builds a motivation for a fault-tolerant transaction coordinator implementation in the two-phase commit protocol by describing…
Curious
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Zookeeper zookeeper.forceSync, Zab and Paxos
I noticed that the default the configuration for zookeeper.forceSync is "no".
This mean FileChannel.Force() will not be called on the Write ahead log.
I was under the impression that for the Zab consensus algorithm used by zookeeper to work…
skyde
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Paxos made simple choosing proposing value
The paper says:
1.A proposer chooses a new proposal number n and sends a request to each member of some set of acceptors, asking it to respond with:
(a) A promise never again to accept a proposal numbered less than n, and
(b) The proposal with the…
ideawu
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In paxos, what happens if a proposer is down after its proposal is rejected?
In this figure, the proposal of X is rejected.
At the end of the timeline, S1 and S2 accept X while S3, S4 and S5 accept Y. Proposer X is now supposed to re-send the proposal with value Y.
But what happens if proposer X gets down at that time? How…
daquexian
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