org.elasticsearch.cluster.routing.ShardRouting Maven / Gradle / Ivy
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* ownership. Elasticsearch licenses this file to you under
* the Apache License, Version 2.0 (the "License"); you may
* not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
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* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
package org.elasticsearch.cluster.routing;
import org.elasticsearch.common.Nullable;
import org.elasticsearch.common.io.stream.StreamInput;
import org.elasticsearch.common.io.stream.StreamOutput;
import org.elasticsearch.common.io.stream.Streamable;
import org.elasticsearch.common.xcontent.ToXContent;
import org.elasticsearch.common.xcontent.XContentBuilder;
import org.elasticsearch.index.shard.ShardId;
import java.io.IOException;
import java.util.Collections;
import java.util.List;
/**
* {@link ShardRouting} immutably encapsulates information about shard
* routings like id, state, version, etc.
*/
public final class ShardRouting implements Streamable, ToXContent {
/**
* Used if shard size is not available
*/
public static final long UNAVAILABLE_EXPECTED_SHARD_SIZE = -1;
private String index;
private int shardId;
private String currentNodeId;
private String relocatingNodeId;
private boolean primary;
private ShardRoutingState state;
private long version;
private RestoreSource restoreSource;
private UnassignedInfo unassignedInfo;
private AllocationId allocationId;
private final transient List asList;
private transient ShardId shardIdentifier;
private boolean frozen = false;
private long expectedShardSize = UNAVAILABLE_EXPECTED_SHARD_SIZE;
private ShardRouting() {
this.asList = Collections.singletonList(this);
}
public ShardRouting(ShardRouting copy) {
this(copy, copy.version());
}
public ShardRouting(ShardRouting copy, long version) {
this(copy.index(), copy.id(), copy.currentNodeId(), copy.relocatingNodeId(), copy.restoreSource(), copy.primary(), copy.state(), version, copy.unassignedInfo(), copy.allocationId(), true, copy.getExpectedShardSize());
}
/**
* A constructor to internally create shard routing instances, note, the internal flag should only be set to true
* by either this class or tests. Visible for testing.
*/
ShardRouting(String index, int shardId, String currentNodeId,
String relocatingNodeId, RestoreSource restoreSource, boolean primary, ShardRoutingState state, long version,
UnassignedInfo unassignedInfo, AllocationId allocationId, boolean internal, long expectedShardSize) {
this.index = index;
this.shardId = shardId;
this.currentNodeId = currentNodeId;
this.relocatingNodeId = relocatingNodeId;
this.primary = primary;
this.state = state;
this.asList = Collections.singletonList(this);
this.version = version;
this.restoreSource = restoreSource;
this.unassignedInfo = unassignedInfo;
this.allocationId = allocationId;
this.expectedShardSize = expectedShardSize;
assert expectedShardSize == UNAVAILABLE_EXPECTED_SHARD_SIZE || state == ShardRoutingState.INITIALIZING || state == ShardRoutingState.RELOCATING : expectedShardSize + " state: " + state;
assert expectedShardSize >= 0 || state != ShardRoutingState.INITIALIZING || state != ShardRoutingState.RELOCATING : expectedShardSize + " state: " + state;
assert !(state == ShardRoutingState.UNASSIGNED && unassignedInfo == null) : "unassigned shard must be created with meta";
if (!internal) {
assert state == ShardRoutingState.UNASSIGNED;
assert currentNodeId == null;
assert relocatingNodeId == null;
assert allocationId == null;
}
}
/**
* Creates a new unassigned shard.
*/
public static ShardRouting newUnassigned(String index, int shardId, RestoreSource restoreSource, boolean primary, UnassignedInfo unassignedInfo) {
return new ShardRouting(index, shardId, null, null, restoreSource, primary, ShardRoutingState.UNASSIGNED, 0, unassignedInfo, null, true, UNAVAILABLE_EXPECTED_SHARD_SIZE);
}
/**
* The index name.
*/
public String index() {
return this.index;
}
/**
* The index name.
*/
public String getIndex() {
return index();
}
/**
* The shard id.
*/
public int id() {
return this.shardId;
}
/**
* The shard id.
*/
public int getId() {
return id();
}
/**
* The routing version associated with the shard.
*/
public long version() {
return this.version;
}
/**
* The shard is unassigned (not allocated to any node).
*/
public boolean unassigned() {
return state == ShardRoutingState.UNASSIGNED;
}
/**
* The shard is initializing (usually recovering either from peer shard
* or from gateway).
*/
public boolean initializing() {
return state == ShardRoutingState.INITIALIZING;
}
/**
* Returns true iff the this shard is currently
* {@link ShardRoutingState#STARTED started} or
* {@link ShardRoutingState#RELOCATING relocating} to another node.
* Otherwise false
*/
public boolean active() {
return started() || relocating();
}
/**
* The shard is in started mode.
*/
public boolean started() {
return state == ShardRoutingState.STARTED;
}
/**
* Returns true iff the this shard is currently relocating to
* another node. Otherwise false
*
* @see ShardRoutingState#RELOCATING
*/
public boolean relocating() {
return state == ShardRoutingState.RELOCATING;
}
/**
* Returns true iff this shard is assigned to a node ie. not
* {@link ShardRoutingState#UNASSIGNED unassigned}. Otherwise false
*/
public boolean assignedToNode() {
return currentNodeId != null;
}
/**
* The current node id the shard is allocated on.
*/
public String currentNodeId() {
return this.currentNodeId;
}
/**
* The relocating node id the shard is either relocating to or relocating from.
*/
public String relocatingNodeId() {
return this.relocatingNodeId;
}
/**
* Creates a shard routing representing the target shard.
* The target shard routing will be the INITIALIZING state and have relocatingNodeId set to the
* source node.
*/
public ShardRouting buildTargetRelocatingShard() {
assert relocating();
return new ShardRouting(index, shardId, relocatingNodeId, currentNodeId, restoreSource, primary, ShardRoutingState.INITIALIZING, version, unassignedInfo,
AllocationId.newTargetRelocation(allocationId), true, expectedShardSize);
}
/**
* Snapshot id and repository where this shard is being restored from
*/
public RestoreSource restoreSource() {
return restoreSource;
}
/**
* Additional metadata on why the shard is/was unassigned. The metadata is kept around
* until the shard moves to STARTED.
*/
@Nullable
public UnassignedInfo unassignedInfo() {
return unassignedInfo;
}
/**
* An id that uniquely identifies an allocation.
*/
@Nullable
public AllocationId allocationId() {
return this.allocationId;
}
/**
* Returns true iff this shard is a primary.
*/
public boolean primary() {
return this.primary;
}
/**
* The shard state.
*/
public ShardRoutingState state() {
return this.state;
}
/**
* The shard id.
*/
public ShardId shardId() {
if (shardIdentifier != null) {
return shardIdentifier;
}
shardIdentifier = new ShardId(index, shardId);
return shardIdentifier;
}
public boolean allocatedPostIndexCreate() {
if (active()) {
return true;
}
// unassigned info is only cleared when a shard moves to started, so
// for unassigned and initializing (we checked for active() before),
// we can safely assume it is there
if (unassignedInfo.getReason() == UnassignedInfo.Reason.INDEX_CREATED) {
return false;
}
return true;
}
/**
* A shard iterator with just this shard in it.
*/
public ShardIterator shardsIt() {
return new PlainShardIterator(shardId(), asList);
}
public static ShardRouting readShardRoutingEntry(StreamInput in) throws IOException {
ShardRouting entry = new ShardRouting();
entry.readFrom(in);
return entry;
}
public static ShardRouting readShardRoutingEntry(StreamInput in, String index, int shardId) throws IOException {
ShardRouting entry = new ShardRouting();
entry.readFrom(in, index, shardId);
return entry;
}
public void readFrom(StreamInput in, String index, int shardId) throws IOException {
this.index = index;
this.shardId = shardId;
readFromThin(in);
}
public void readFromThin(StreamInput in) throws IOException {
version = in.readLong();
if (in.readBoolean()) {
currentNodeId = in.readString();
}
if (in.readBoolean()) {
relocatingNodeId = in.readString();
}
primary = in.readBoolean();
state = ShardRoutingState.fromValue(in.readByte());
restoreSource = RestoreSource.readOptionalRestoreSource(in);
if (in.readBoolean()) {
unassignedInfo = new UnassignedInfo(in);
}
if (in.readBoolean()) {
allocationId = new AllocationId(in);
}
if (relocating() || initializing()) {
expectedShardSize = in.readLong();
} else {
expectedShardSize = UNAVAILABLE_EXPECTED_SHARD_SIZE;
}
freeze();
}
@Override
public void readFrom(StreamInput in) throws IOException {
readFrom(in, in.readString(), in.readVInt());
}
/**
* Writes shard information to {@link StreamOutput} without writing index name and shard id
*
* @param out {@link StreamOutput} to write shard information to
* @throws IOException if something happens during write
*/
public void writeToThin(StreamOutput out) throws IOException {
out.writeLong(version);
if (currentNodeId != null) {
out.writeBoolean(true);
out.writeString(currentNodeId);
} else {
out.writeBoolean(false);
}
if (relocatingNodeId != null) {
out.writeBoolean(true);
out.writeString(relocatingNodeId);
} else {
out.writeBoolean(false);
}
out.writeBoolean(primary);
out.writeByte(state.value());
if (restoreSource != null) {
out.writeBoolean(true);
restoreSource.writeTo(out);
} else {
out.writeBoolean(false);
}
if (unassignedInfo != null) {
out.writeBoolean(true);
unassignedInfo.writeTo(out);
} else {
out.writeBoolean(false);
}
if (allocationId != null) {
out.writeBoolean(true);
allocationId.writeTo(out);
} else {
out.writeBoolean(false);
}
if (relocating() || initializing()) {
out.writeLong(expectedShardSize);
}
}
@Override
public void writeTo(StreamOutput out) throws IOException {
out.writeString(index);
out.writeVInt(shardId);
writeToThin(out);
}
public void updateUnassignedInfo(UnassignedInfo unassignedInfo) {
ensureNotFrozen();
assert this.unassignedInfo != null : "can only update unassign info if they are already set";
this.unassignedInfo = unassignedInfo;
}
// package private mutators start here
/**
* Moves the shard to unassigned state.
*/
void moveToUnassigned(UnassignedInfo unassignedInfo) {
ensureNotFrozen();
version++;
assert state != ShardRoutingState.UNASSIGNED : this;
state = ShardRoutingState.UNASSIGNED;
currentNodeId = null;
relocatingNodeId = null;
this.unassignedInfo = unassignedInfo;
allocationId = null;
expectedShardSize = UNAVAILABLE_EXPECTED_SHARD_SIZE;
}
/**
* Initializes an unassigned shard on a node.
*/
void initialize(String nodeId, long expectedShardSize) {
ensureNotFrozen();
version++;
assert state == ShardRoutingState.UNASSIGNED : this;
assert relocatingNodeId == null : this;
state = ShardRoutingState.INITIALIZING;
currentNodeId = nodeId;
allocationId = AllocationId.newInitializing();
this.expectedShardSize = expectedShardSize;
}
/**
* Relocate the shard to another node.
*
* @param relocatingNodeId id of the node to relocate the shard
*/
void relocate(String relocatingNodeId, long expectedShardSize) {
ensureNotFrozen();
version++;
assert state == ShardRoutingState.STARTED : "current shard has to be started in order to be relocated " + this;
state = ShardRoutingState.RELOCATING;
this.relocatingNodeId = relocatingNodeId;
this.allocationId = AllocationId.newRelocation(allocationId);
this.expectedShardSize = expectedShardSize;
}
/**
* Cancel relocation of a shard. The shards state must be set
* to RELOCATING.
*/
void cancelRelocation() {
ensureNotFrozen();
version++;
assert state == ShardRoutingState.RELOCATING : this;
assert assignedToNode() : this;
assert relocatingNodeId != null : this;
expectedShardSize = UNAVAILABLE_EXPECTED_SHARD_SIZE;
state = ShardRoutingState.STARTED;
relocatingNodeId = null;
allocationId = AllocationId.cancelRelocation(allocationId);
}
/**
* Moves the shard from started to initializing
*/
void reinitializeShard() {
ensureNotFrozen();
assert state == ShardRoutingState.STARTED;
version++;
state = ShardRoutingState.INITIALIZING;
allocationId = AllocationId.newInitializing();
this.unassignedInfo = new UnassignedInfo(UnassignedInfo.Reason.REINITIALIZED, null);
}
/**
* Set the shards state to STARTED. The shards state must be
* INITIALIZING or RELOCATING. Any relocation will be
* canceled.
*/
void moveToStarted() {
ensureNotFrozen();
version++;
assert state == ShardRoutingState.INITIALIZING : "expected an initializing shard " + this;
relocatingNodeId = null;
restoreSource = null;
unassignedInfo = null; // we keep the unassigned data until the shard is started
if (allocationId.getRelocationId() != null) {
// relocation target
allocationId = AllocationId.finishRelocation(allocationId);
}
expectedShardSize = UNAVAILABLE_EXPECTED_SHARD_SIZE;
state = ShardRoutingState.STARTED;
}
/**
* Make the shard primary unless it's not Primary
* //TODO: doc exception
*/
void moveToPrimary() {
ensureNotFrozen();
version++;
if (primary) {
throw new IllegalShardRoutingStateException(this, "Already primary, can't move to primary");
}
primary = true;
}
/**
* Set the primary shard to non-primary
*/
void moveFromPrimary() {
ensureNotFrozen();
version++;
if (!primary) {
throw new IllegalShardRoutingStateException(this, "Not primary, can't move to replica");
}
primary = false;
}
/** returns true if this routing has the same shardId as another */
public boolean isSameShard(ShardRouting other) {
return index.equals(other.index) && shardId == other.shardId;
}
/**
* returns true if this routing has the same allocation ID as another.
*
* Note: if both shard routing has a null as their {@link #allocationId()}, this method returns false as the routing describe
* no allocation at all..
**/
public boolean isSameAllocation(ShardRouting other) {
boolean b = this.allocationId != null && other.allocationId != null && this.allocationId.getId().equals(other.allocationId.getId());
assert b == false || this.currentNodeId.equals(other.currentNodeId) : "ShardRoutings have the same allocation id but not the same node. This [" + this + "], other [" + other + "]";
return b;
}
/**
* Returns true if this shard is a relocation target for another shard (i.e., was created with {@link #buildTargetRelocatingShard()}
*/
public boolean isRelocationTarget() {
return state == ShardRoutingState.INITIALIZING && relocatingNodeId != null;
}
/** returns true if the routing is the relocation target of the given routing */
public boolean isRelocationTargetOf(ShardRouting other) {
boolean b = this.allocationId != null && other.allocationId != null && this.state == ShardRoutingState.INITIALIZING &&
this.allocationId.getId().equals(other.allocationId.getRelocationId());
assert b == false || other.state == ShardRoutingState.RELOCATING :
"ShardRouting is a relocation target but the source shard state isn't relocating. This [" + this + "], other [" + other + "]";
assert b == false || other.allocationId.getId().equals(this.allocationId.getRelocationId()) :
"ShardRouting is a relocation target but the source id isn't equal to source's allocationId.getRelocationId. This [" + this + "], other [" + other + "]";
assert b == false || other.currentNodeId().equals(this.relocatingNodeId) :
"ShardRouting is a relocation target but source current node id isn't equal to target relocating node. This [" + this + "], other [" + other + "]";
assert b == false || this.currentNodeId().equals(other.relocatingNodeId) :
"ShardRouting is a relocation target but current node id isn't equal to source relocating node. This [" + this + "], other [" + other + "]";
assert b == false || isSameShard(other) :
"ShardRouting is a relocation target but both routings are not of the same shard. This [" + this + "], other [" + other + "]";
assert b == false || this.primary == other.primary :
"ShardRouting is a relocation target but primary flag is different. This [" + this + "], target [" + other + "]";
return b;
}
/** returns true if the routing is the relocation source for the given routing */
public boolean isRelocationSourceOf(ShardRouting other) {
boolean b = this.allocationId != null && other.allocationId != null && other.state == ShardRoutingState.INITIALIZING &&
other.allocationId.getId().equals(this.allocationId.getRelocationId());
assert b == false || this.state == ShardRoutingState.RELOCATING :
"ShardRouting is a relocation source but shard state isn't relocating. This [" + this + "], other [" + other + "]";
assert b == false || this.allocationId.getId().equals(other.allocationId.getRelocationId()) :
"ShardRouting is a relocation source but the allocation id isn't equal to other.allocationId.getRelocationId. This [" + this + "], other [" + other + "]";
assert b == false || this.currentNodeId().equals(other.relocatingNodeId) :
"ShardRouting is a relocation source but current node isn't equal to other's relocating node. This [" + this + "], other [" + other + "]";
assert b == false || other.currentNodeId().equals(this.relocatingNodeId) :
"ShardRouting is a relocation source but relocating node isn't equal to other's current node. This [" + this + "], other [" + other + "]";
assert b == false || isSameShard(other) :
"ShardRouting is a relocation source but both routings are not of the same shard. This [" + this + "], target [" + other + "]";
assert b == false || this.primary == other.primary :
"ShardRouting is a relocation source but primary flag is different. This [" + this + "], target [" + other + "]";
return b;
}
/** returns true if the current routing is identical to the other routing in all but meta fields, i.e., version and unassigned info */
public boolean equalsIgnoringMetaData(ShardRouting other) {
if (primary != other.primary) {
return false;
}
if (shardId != other.shardId) {
return false;
}
if (currentNodeId != null ? !currentNodeId.equals(other.currentNodeId) : other.currentNodeId != null) {
return false;
}
if (index != null ? !index.equals(other.index) : other.index != null) {
return false;
}
if (relocatingNodeId != null ? !relocatingNodeId.equals(other.relocatingNodeId) : other.relocatingNodeId != null) {
return false;
}
if (allocationId != null ? !allocationId.equals(other.allocationId) : other.allocationId != null) {
return false;
}
if (state != other.state) {
return false;
}
if (restoreSource != null ? !restoreSource.equals(other.restoreSource) : other.restoreSource != null) {
return false;
}
return true;
}
@Override
public boolean equals(Object o) {
if (this == o) {
return true;
}
// we check on instanceof so we also handle the ImmutableShardRouting case as well
if (o == null || !(o instanceof ShardRouting)) {
return false;
}
ShardRouting that = (ShardRouting) o;
if (version != that.version) {
return false;
}
if (unassignedInfo != null ? !unassignedInfo.equals(that.unassignedInfo) : that.unassignedInfo != null) {
return false;
}
return equalsIgnoringMetaData(that);
}
private long hashVersion = version - 1;
private int hashCode = 0;
@Override
public int hashCode() {
if (hashVersion == version) {
return hashCode;
}
int result = index != null ? index.hashCode() : 0;
result = 31 * result + shardId;
result = 31 * result + (currentNodeId != null ? currentNodeId.hashCode() : 0);
result = 31 * result + (relocatingNodeId != null ? relocatingNodeId.hashCode() : 0);
result = 31 * result + (primary ? 1 : 0);
result = 31 * result + (state != null ? state.hashCode() : 0);
result = 31 * result + (int) (version ^ (version >>> 32));
result = 31 * result + (restoreSource != null ? restoreSource.hashCode() : 0);
result = 31 * result + (allocationId != null ? allocationId.hashCode() : 0);
result = 31 * result + (unassignedInfo != null ? unassignedInfo.hashCode() : 0);
return hashCode = result;
}
@Override
public String toString() {
return shortSummary();
}
/**
* A short description of the shard.
*/
public String shortSummary() {
StringBuilder sb = new StringBuilder();
sb.append('[').append(index).append(']').append('[').append(shardId).append(']');
sb.append(", node[").append(currentNodeId).append("], ");
if (relocatingNodeId != null) {
sb.append("relocating [").append(relocatingNodeId).append("], ");
}
if (primary) {
sb.append("[P]");
} else {
sb.append("[R]");
}
sb.append(", v[").append(version).append("]");
if (this.restoreSource != null) {
sb.append(", restoring[" + restoreSource + "]");
}
sb.append(", s[").append(state).append("]");
if (allocationId != null) {
sb.append(", a").append(allocationId);
}
if (this.unassignedInfo != null) {
sb.append(", ").append(unassignedInfo.toString());
}
if (expectedShardSize != UNAVAILABLE_EXPECTED_SHARD_SIZE) {
sb.append(", expected_shard_size[").append(expectedShardSize).append("]");
}
return sb.toString();
}
@Override
public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
builder.startObject()
.field("state", state())
.field("primary", primary())
.field("node", currentNodeId())
.field("relocating_node", relocatingNodeId())
.field("shard", shardId().id())
.field("index", shardId().index().name())
.field("version", version);
if (expectedShardSize != UNAVAILABLE_EXPECTED_SHARD_SIZE) {
builder.field("expected_shard_size_in_bytes", expectedShardSize);
}
if (restoreSource() != null) {
builder.field("restore_source");
restoreSource().toXContent(builder, params);
}
if (allocationId != null) {
allocationId.toXContent(builder, params);
}
if (unassignedInfo != null) {
unassignedInfo.toXContent(builder, params);
}
return builder.endObject();
}
private void ensureNotFrozen() {
if (frozen) {
throw new IllegalStateException("ShardRouting can't be modified anymore - already frozen");
}
}
void freeze() {
frozen = true;
}
boolean isFrozen() {
return frozen;
}
/**
* Returns the expected shard size for {@link ShardRoutingState#RELOCATING} and {@link ShardRoutingState#INITIALIZING}
* shards. If it's size is not available {@value #UNAVAILABLE_EXPECTED_SHARD_SIZE} will be returned.
*/
public long getExpectedShardSize() {
return expectedShardSize;
}
}