Examples with GroupMember io.atomix.primitive.partition.GroupMember used on opensource projects

Example 1 with GroupMember

use of io.atomix.primitive.partition.GroupMember in project atomix by atomix.

the class HashBasedPrimaryElection method recomputeTerm.

/**
 * Recomputes the current term.
 */
private synchronized void recomputeTerm(PartitionGroupMembership membership) {
    if (membership == null) {
        return;
    }
    // Create a list of candidates based on the availability of members in the group.
    List<GroupMember> candidates = new ArrayList<>();
    for (MemberId memberId : membership.members()) {
        Member member = clusterMembershipService.getMember(memberId);
        if (member != null && member.isReachable()) {
            candidates.add(new GroupMember(memberId, MemberGroupId.from(memberId.id())));
        }
    }
    // Sort the candidates by a hash of their member ID.
    candidates.sort((a, b) -> {
        int aoffset = Hashing.murmur3_32().hashString(a.memberId().id(), StandardCharsets.UTF_8).asInt() % partitionId.id();
        int boffset = Hashing.murmur3_32().hashString(b.memberId().id(), StandardCharsets.UTF_8).asInt() % partitionId.id();
        return aoffset - boffset;
    });
    // Store the current term in a local variable avoid repeated volatile reads.
    PrimaryTerm currentTerm = this.currentTerm;
    // Compute the primary from the sorted candidates list.
    GroupMember primary = candidates.isEmpty() ? null : candidates.get(0);
    // Remove the primary from the candidates list.
    candidates = candidates.isEmpty() ? Collections.emptyList() : candidates.subList(1, candidates.size());
    // If the primary has changed, increment the term. Otherwise, use the current term from the replicated counter.
    long term = currentTerm != null && Objects.equals(currentTerm.primary(), primary) && Objects.equals(currentTerm.candidates(), candidates) ? currentTerm() : incrementTerm();
    // Create the new primary term. If the term has changed update the term and trigger an event.
    PrimaryTerm newTerm = new PrimaryTerm(term, primary, candidates);
    if (!Objects.equals(currentTerm, newTerm)) {
        this.currentTerm = newTerm;
        LOGGER.debug("{} - Recomputed term for partition {}: {}", clusterMembershipService.getLocalMember().id(), partitionId, newTerm);
        post(new PrimaryElectionEvent(PrimaryElectionEvent.Type.CHANGED, partitionId, newTerm));
        broadcastCounters();
    }
}

Example 2 with GroupMember

use of io.atomix.primitive.partition.GroupMember in project atomix by atomix.

the class PrimaryElectorServiceTest method testEnterSeveralPartitions.

@Test
public void testEnterSeveralPartitions() {
    PrimaryElectorService elector = newService();
    PrimaryTerm term = null;
    int numParts = 10;
    int numMembers = 20;
    List<List<GroupMember>> allMembers = new ArrayList<>();
    List<PrimaryTerm> terms = new ArrayList<>();
    for (int p = 0; p < numParts; p++) {
        PartitionId partId = new PartitionId("test", p);
        allMembers.add(new ArrayList<>());
        // Add all members in same group.
        for (int i = 0; i < numMembers; i++) {
            GroupMember m = createGroupMember("node" + i, "group1");
            allMembers.get(p).add(m);
            Session<?> s = createSession(m);
            term = elector.enter(createEnterOp(partId, m, s));
        }
        if (term != null) {
            terms.add(term);
        }
    }
    // Check primary and candidates in each partition.
    for (int p = 0; p < numParts; p++) {
        assertEquals(1L, terms.get(p).term());
        assertEquals(allMembers.get(p).get(0), terms.get(p).primary());
        assertEquals(numMembers, terms.get(p).candidates().size());
        for (int i = 0; i < numMembers; i++) {
            assertEquals(allMembers.get(p).get(i), terms.get(p).candidates().get(i));
        }
    }
}

Example 3 with GroupMember

use of io.atomix.primitive.partition.GroupMember in project atomix by atomix.

the class PrimaryElectorServiceTest method testEnterAndExpireSessions.

@Test
public void testEnterAndExpireSessions() {
    PrimaryElectorService elector = newService();
    PartitionId partId = new PartitionId("test", 1);
    PrimaryTerm term = null;
    int numMembers = 9;
    // Add 9 members in 3 different groups.
    List<Session<?>> sessions = new ArrayList<>();
    List<GroupMember> members = new ArrayList<>();
    for (int i = 0; i < numMembers; i++) {
        GroupMember m = createGroupMember("node" + i, "group" + (i / 3));
        members.add(m);
        Session<?> s = createSession(m);
        sessions.add(s);
        term = elector.enter(createEnterOp(partId, m, s));
    }
    // Check current primary.
    assertEquals(1L, term.term());
    assertEquals(members.get(0), term.primary());
    assertEquals(numMembers, term.candidates().size());
    List<GroupMember> backups1 = term.backups(2);
    assertEquals(members.get(3), backups1.get(0));
    assertEquals(members.get(6), backups1.get(1));
    // Expire session of primary and check new term.
    // New primary should be the first of the old backups.
    elector.onExpire(sessions.get(0));
    term = elector.getTerm(createGetTermOp(partId, members.get(3), sessions.get(3)));
    assertEquals(2L, term.term());
    assertEquals(members.get(3), term.primary());
    assertEquals(numMembers - 1, term.candidates().size());
    List<GroupMember> backups2 = term.backups(2);
    assertEquals(members.get(6), backups2.get(0));
    assertEquals(members.get(1), backups2.get(1));
    // Expire session of backup and check term updated.
    elector.onExpire(sessions.get(6));
    term = elector.getTerm(createGetTermOp(partId, members.get(5), sessions.get(5)));
    assertEquals(2L, term.term());
    assertEquals(members.get(3), term.primary());
    assertEquals(numMembers - 2, term.candidates().size());
    List<GroupMember> backups3 = term.backups(2);
    assertEquals(members.get(1), backups3.get(0));
    assertEquals(members.get(4), backups3.get(1));
}

Example 4 with GroupMember

use of io.atomix.primitive.partition.GroupMember in project atomix by atomix.

the class PrimaryElectorServiceTest method testEnterSinglePartitionWithGroups.

@Test
public void testEnterSinglePartitionWithGroups() {
    PrimaryElectorService elector = newService();
    PartitionId partId = new PartitionId("test", 1);
    PrimaryTerm term = null;
    int numMembers = 9;
    // Add 9 members in 3 different groups.
    List<GroupMember> members = new ArrayList<>();
    for (int i = 0; i < numMembers; i++) {
        GroupMember m = createGroupMember("node" + i, "group" + (i / 3));
        members.add(m);
        Session<?> s = createSession(m);
        term = elector.enter(createEnterOp(partId, m, s));
    }
    // Check primary and candidates.
    assertEquals(1L, term.term());
    assertEquals(members.get(0), term.primary());
    assertEquals(numMembers, term.candidates().size());
    // Check backups are selected in different groups.
    List<GroupMember> backups2 = term.backups(2);
    assertEquals(members.get(3), backups2.get(0));
    assertEquals(members.get(6), backups2.get(1));
    List<GroupMember> backups3 = term.backups(3);
    assertEquals(members.get(3), backups3.get(0));
    assertEquals(members.get(6), backups3.get(1));
    assertEquals(members.get(1), backups3.get(2));
}

Example 5 with GroupMember

use of io.atomix.primitive.partition.GroupMember in project atomix by atomix.

the class DistributedLogServerContext method start.

@Override
public CompletableFuture<Void> start() {
    registerListeners();
    compactTimer = threadContext.schedule(Duration.ofSeconds(30), this::compact);
    return memberGroupService.start().thenComposeAsync(v -> {
        MemberGroup group = memberGroupService.getMemberGroup(clusterMembershipService.getLocalMember());
        primaryElection.addListener(primaryElectionListener);
        if (group != null) {
            return primaryElection.enter(new GroupMember(clusterMembershipService.getLocalMember().id(), group.id())).thenApply(term -> {
                changeRole(term);
                return null;
            });
        }
        return CompletableFuture.completedFuture(null);
    }, threadContext).thenApply(v -> {
        started.set(true);
        return null;
    });
}