Java IEndpointSnitch.sortByProximity方法代码示例

import org.apache.cassandra.locator.IEndpointSnitch; //导入方法依赖的package包/类
/**
 * Find a suitable replica as leader for counter update.
 * For now, we pick a random replica in the local DC (or ask the snitch if
 * there is no replica alive in the local DC).
 * TODO: if we track the latency of the counter writes (which makes sense
 * contrarily to standard writes since there is a read involved), we could
 * trust the dynamic snitch entirely, which may be a better solution. It
 * is unclear we want to mix those latencies with read latencies, so this
 * may be a bit involved.
 */
private static InetAddress findSuitableEndpoint(String table, ByteBuffer key, String localDataCenter) throws UnavailableException
{
    IEndpointSnitch snitch = DatabaseDescriptor.getEndpointSnitch();
    List<InetAddress> endpoints = StorageService.instance.getLiveNaturalEndpoints(table, key);
    if (endpoints.isEmpty())
        throw new UnavailableException();

    List<InetAddress> localEndpoints = new ArrayList<InetAddress>();
    for (InetAddress endpoint : endpoints)
    {
        if (snitch.getDatacenter(endpoint).equals(localDataCenter))
            localEndpoints.add(endpoint);
    }
    if (localEndpoints.isEmpty())
    {
        // No endpoint in local DC, pick the closest endpoint according to the snitch
        snitch.sortByProximity(FBUtilities.getLocalAddress(), endpoints);
        return endpoints.get(0);
    }
    else
    {
        return localEndpoints.get(FBUtilities.threadLocalRandom().nextInt(localEndpoints.size()));
    }
}
 

import org.apache.cassandra.locator.IEndpointSnitch; //导入方法依赖的package包/类
/**
 * Find a suitable replica as leader for counter update.
 * For now, we pick a random replica in the local DC (or ask the snitch if
 * there is no replica alive in the local DC).
 * TODO: if we track the latency of the counter writes (which makes sense
 * contrarily to standard writes since there is a read involved), we could
 * trust the dynamic snitch entirely, which may be a better solution. It
 * is unclear we want to mix those latencies with read latencies, so this
 * may be a bit involved.
 */
private static InetAddress findSuitableEndpoint(String keyspaceName, ByteBuffer key, String localDataCenter, ConsistencyLevel cl) throws UnavailableException
{
    Keyspace keyspace = Keyspace.open(keyspaceName);
    IEndpointSnitch snitch = DatabaseDescriptor.getEndpointSnitch();
    List<InetAddress> endpoints = StorageService.instance.getLiveNaturalEndpoints(keyspace, key);
    if (endpoints.isEmpty())
        // TODO have a way to compute the consistency level
        throw new UnavailableException(cl, cl.blockFor(keyspace), 0);

    List<InetAddress> localEndpoints = new ArrayList<InetAddress>();
    for (InetAddress endpoint : endpoints)
    {
        if (snitch.getDatacenter(endpoint).equals(localDataCenter))
            localEndpoints.add(endpoint);
    }
    if (localEndpoints.isEmpty())
    {
        // No endpoint in local DC, pick the closest endpoint according to the snitch
        snitch.sortByProximity(FBUtilities.getBroadcastAddress(), endpoints);
        return endpoints.get(0);
    }
    else
    {
        return localEndpoints.get(ThreadLocalRandom.current().nextInt(localEndpoints.size()));
    }
}
 

import org.apache.cassandra.locator.IEndpointSnitch; //导入方法依赖的package包/类
private static Collection<InetAddress> getBatchlogEndpoints(String localDataCenter, ConsistencyLevel consistencyLevel) throws UnavailableException
{
    // will include every known node in the DC, including localhost.
    TokenMetadata.Topology topology = StorageService.instance.getTokenMetadata().cloneOnlyTokenMap().getTopology();
    Collection<InetAddress> localMembers = topology.getDatacenterEndpoints().get(localDataCenter);

    // special case for single-node datacenters
    if (localMembers.size() == 1)
        return localMembers;

    // not a single-node cluster - don't count the local node.
    localMembers.remove(FBUtilities.getBroadcastAddress());

    // include only alive nodes
    List<InetAddress> candidates = new ArrayList<InetAddress>(localMembers.size());
    for (InetAddress member : localMembers)
    {
        if (FailureDetector.instance.isAlive(member))
            candidates.add(member);
    }

    if (candidates.isEmpty())
    {
        if (consistencyLevel == ConsistencyLevel.ANY)
            return Collections.singleton(FBUtilities.getBroadcastAddress());

        throw new UnavailableException(ConsistencyLevel.ONE, 1, 0);
    }

    if (candidates.size() > 2)
    {
        IEndpointSnitch snitch = DatabaseDescriptor.getEndpointSnitch();
        snitch.sortByProximity(FBUtilities.getBroadcastAddress(), candidates);
        candidates = candidates.subList(0, 2);
    }

    return candidates;
}
 

import org.apache.cassandra.locator.IEndpointSnitch; //导入方法依赖的package包/类
/**
 * Find a suitable replica as leader for counter update.
 * For now, we pick a random replica in the local DC (or ask the snitch if
 * there is no replica alive in the local DC).
 * TODO: if we track the latency of the counter writes (which makes sense
 * contrarily to standard writes since there is a read involved), we could
 * trust the dynamic snitch entirely, which may be a better solution. It
 * is unclear we want to mix those latencies with read latencies, so this
 * may be a bit involved.
 */
private static InetAddress findSuitableEndpoint(String keyspaceName, ByteBuffer key, String localDataCenter, ConsistencyLevel cl) throws UnavailableException
{
    Keyspace keyspace = Keyspace.open(keyspaceName);
    IEndpointSnitch snitch = DatabaseDescriptor.getEndpointSnitch();
    List<InetAddress> endpoints = StorageService.instance.getLiveNaturalEndpoints(keyspace, key);
    if (endpoints.isEmpty())
        // TODO have a way to compute the consistency level
        throw new UnavailableException(cl, cl.blockFor(keyspace), 0);

    List<InetAddress> localEndpoints = new ArrayList<InetAddress>();
    for (InetAddress endpoint : endpoints)
    {
        if (snitch.getDatacenter(endpoint).equals(localDataCenter))
            localEndpoints.add(endpoint);
    }
    if (localEndpoints.isEmpty())
    {
        // No endpoint in local DC, pick the closest endpoint according to the snitch
        snitch.sortByProximity(FBUtilities.getBroadcastAddress(), endpoints);
        return endpoints.get(0);
    }
    else
    {
        return localEndpoints.get(FBUtilities.threadLocalRandom().nextInt(localEndpoints.size()));
    }
}
 

import org.apache.cassandra.locator.IEndpointSnitch; //导入方法依赖的package包/类
private static Collection<InetAddress> getBatchlogEndpoints(String localDataCenter) throws UnavailableException
{
    // will include every known node in the DC, including localhost.
    TokenMetadata.Topology topology = StorageService.instance.getTokenMetadata().cloneOnlyTokenMap().getTopology();
    Collection<InetAddress> localMembers = topology.getDatacenterEndpoints().get(localDataCenter);

    // special case for single-node datacenters
    if (localMembers.size() == 1)
        return localMembers;

    // not a single-node cluster - don't count the local node.
    localMembers.remove(FBUtilities.getBroadcastAddress());

    // include only alive nodes
    List<InetAddress> candidates = new ArrayList<InetAddress>(localMembers.size());
    for (InetAddress member : localMembers)
    {
        if (FailureDetector.instance.isAlive(member))
            candidates.add(member);
    }

    if (candidates.isEmpty())
        throw new UnavailableException(ConsistencyLevel.ONE, 1, 0);

    if (candidates.size() > 2)
    {
        IEndpointSnitch snitch = DatabaseDescriptor.getEndpointSnitch();
        snitch.sortByProximity(FBUtilities.getBroadcastAddress(), candidates);
        candidates = candidates.subList(0, 2);
    }

    return candidates;
}
 

import org.apache.cassandra.locator.IEndpointSnitch; //导入方法依赖的package包/类
/**
 * Find a suitable replica as leader for counter update.
 * For now, we pick a random replica in the local DC (or ask the snitch if
 * there is no replica alive in the local DC).
 * TODO: if we track the latency of the counter writes (which makes sense
 * contrarily to standard writes since there is a read involved), we could
 * trust the dynamic snitch entirely, which may be a better solution. It
 * is unclear we want to mix those latencies with read latencies, so this
 * may be a bit involved.
 */
private static InetAddress findSuitableEndpoint(String tableName, ByteBuffer key, String localDataCenter, ConsistencyLevel cl) throws UnavailableException
{
    Table table = Table.open(tableName);
    IEndpointSnitch snitch = DatabaseDescriptor.getEndpointSnitch();
    List<InetAddress> endpoints = StorageService.instance.getLiveNaturalEndpoints(table, key);
    if (endpoints.isEmpty())
        // TODO have a way to compute the consistency level
        throw new UnavailableException(cl, cl.blockFor(table), 0);

    List<InetAddress> localEndpoints = new ArrayList<InetAddress>();
    for (InetAddress endpoint : endpoints)
    {
        if (snitch.getDatacenter(endpoint).equals(localDataCenter))
            localEndpoints.add(endpoint);
    }
    if (localEndpoints.isEmpty())
    {
        // No endpoint in local DC, pick the closest endpoint according to the snitch
        snitch.sortByProximity(FBUtilities.getBroadcastAddress(), endpoints);
        return endpoints.get(0);
    }
    else
    {
        return localEndpoints.get(FBUtilities.threadLocalRandom().nextInt(localEndpoints.size()));
    }
}