Stack Overflow
Stack Overflow

Questions tagged [leader]

The leader is a software application in a distributed system which provides the global coordination necessary for servers to perform transactions safely and to ensure clients are not oversubscribed.

A file server, time server, or central lock coordinator server can be known as a leader. A combination of central locks on remote procedure calls and explicit locks on file server or time server processes may be necessary to ensure data integrity in a distributed system.

References

44 questions
9
votes
4 answers

What is a partition leader in Apache Kafka?

Are kafka leaders partitions themselves or are they brokers? My initial understanding was that they were partitions which acted as read/write agents which then deffered their value to ISRs. However recently I have been hearing them mentioned as…
Matt
  • 113
  • 1
  • 1
  • 5
9
votes
5 answers

Type of Team Lead: More Programmer || More !Programmer

Yesterday I had a team leader of another team say that they took a while to figure out something I wrote on a wiki page because I referred to obtaining code from source control as "checking out" which apparently confused them. They said that they…
digiarnie
  • 22,305
  • 31
  • 78
  • 126
9
votes
5 answers

How does raft handle committing entries from previous one?

In raft paper section 5.4.2 If a leader crashes before committing an entry, future leaders will attempt to finish replicating the entry. However, a leader cannot immediately conclude that an entry from a previous term is committed once it…
Jal
  • 2,174
  • 1
  • 18
  • 37
9
votes
4 answers

Vim: Leader not working

When trying to use vim-latexsuite's mappings, the ones using Leader are not working: :nmap ---------------------------------------- n rf @Tex_RefreshFolds n ls @Tex_ForwardSearch n lv @Tex_View n …
J0hn D0e
  • 167
  • 1
  • 3
  • 10
6
votes
1 answer

Could Raft elect a leader with uncommitted log?

Suppose a cluster of 5 nodes(ABCDE), node-A is elected leader at the beginning, and while leader-A issues AppendEntries RPCs to the follower(BCDE) to replicate log entry(log-X)，only node-B receives and returns success, at this point leader-A…
Fiken
  • 63
  • 2
6
votes
1 answer

Kafka leader election in multi-dc with an arbiter/witness/observer

I would like to deploy a Kafka cluster in two datacenters with the same number of nodes on each DC. The first DC is used in active mode while the second is in passive mode. For example, let say that both datacenters have 3 nodes with 2 in-sync…
Nicolas Henneaux
  • 11,507
  • 11
  • 57
  • 82
5
votes
2 answers

In Raft when does a follower know an entry became committed? Can an out-of-date node can win a election?

In raft if a log replicated to majority, it is considered as committed in leader. Then leader send msg to follower to tell follower an entry become commit.If not, how and when follower know an entry become committed??? Another question,if an out of…
wang
  • 53
  • 5
4
votes
1 answer

Raft leaders commit a no-op entry at the beginning of their term

Recently I have read a paper on the Raft consensus algorithm. The new leader does not know what is the current commit index. How does a no-op solves this problem?
Chuckie Li
  • 45
  • 7
4
votes
0 answers

paxos when acceptors change its value

In paxos algorithm,there is a description in wiki: Phase 2a: Accept Request If a Proposer receives enough promises from a Quorum of Acceptors, it needs to set a value to its proposal. If any Acceptors had previously accepted any proposal, then…
user1957040
  • 41
  • 2
3
votes
1 answer

Apache Curator LeaderSelector: How to avoid giving up leadership by not exiting from takeLeadership() method?

I'm trying to implement a simple leader election based system where my main business logic of the application runs on the elected leader node. As part of acquiring leadership, the main business logic starts various other services. I'm using Apache…
sumeetkm
  • 189
  • 1
  • 7
2
votes
0 answers

Graceful leadership transition in Solr 6.3 and Zookeeper 3.4

Is there a way to initiate a graceful transition of leadership when using a sharded index in Solr 6.3 with Zookeeper 3.4? Thus far the team simply stops the Solr process for the leader. Zookeeper observes the down node and elects the replica. That…
joewyrembelski
  • 156
  • 1
  • 2
  • 8
2
votes
0 answers

what happens if a replica leader in kafka dies after committing a message but before sending Highwater mark to ISR replicas?

From various documentation, I found that after getting acknowledgement from all the ISRs, kafka replica leader sends response back to the producer. After that, the leader periodically broadcast the HW(high water mark) to replicas. (correct me if I…
Ziaul Haque Olive
  • 21
  • 2
2
votes
1 answer

map vim leader key to backspace

The vim documention on how to set the default leader key ( :h mapleader) provides one simple example: :let mapleader = "," I want to map it to backspace and tried a bunch of options, this being the first one: :let mapleader="" But nothing…
Rui Ferrão
  • 199
  • 1
  • 9
2
votes
1 answer

Difference between docker swarm node running as Leader and running as Manager

I wish to understand the difference between docker swarm node running as Leader and running as a Manager. I also, understand that there can be several docker managers but can there be multiple docker swarm Leader nodes and the reasons for it. Note:…
Alijma Hanfi
  • 31
  • 2
2
votes
2 answers

Why Paxos is required for leader election in cassandra

I was reading about the Protocol for distributed consensus and came across the Paxos. It states that you require Paxos for the leader election. Article claiming the same. So, my question is when Cassandra is a ring architecture not master-slave why…
Naresh
  • 5,073
  • 12
  • 67
  • 124
1
2 3