bdeggleston commented on code in PR #4708:
URL: https://github.com/apache/cassandra/pull/4708#discussion_r3432263241
##########
src/java/org/apache/cassandra/locator/SatelliteReplicationStrategy.java:
##########
@@ -513,4 +631,1268 @@ public boolean
hasSameSettings(AbstractReplicationStrategy other)
primaryDC.equals(otherStrategy.primaryDC) &&
disabledDCs.equals(otherStrategy.disabledDCs);
}
+
+ private AbstractReplicationStrategy strategy(ClusterMetadata metadata)
+ {
+ return
metadata.schema.getKeyspaceMetadata(keyspaceName).replicationStrategy;
+ }
+
+ static abstract class CoordinationPlanner<E extends Endpoints<E>, L
extends ReplicaLayout<E>, P extends ReplicaPlan<E, P>>
+ {
+ final ClusterMetadata metadata;
+ final Keyspace keyspace;
+ final ConsistencyLevel cl;
+ final SatelliteReplicationStrategy strategy;
+ final String primary;
+ final String satellite;
+ final List<String> dcs;
+ final L fullLayout;
+ final L liveLayout;
+ final Map<String, L> fullLayouts;
+ final Map<String, L> liveLayouts;
+ final Map<String, E> fullEndpoints;
+ final Map<String, E> liveEndpoints;
+
+ public CoordinationPlanner(ClusterMetadata metadata, Keyspace
keyspace, ConsistencyLevel cl, SatelliteReplicationStrategy strategy, String
primary, L fullLayout)
+ {
+ this.metadata = metadata;
+ this.keyspace = keyspace;
+ this.cl = cl;
+ this.strategy = strategy;
+ this.primary = primary;
+ this.satellite = strategy.getSatelliteForDC(primary);
+
+ this.dcs = createDcList();
+ Preconditions.checkState(!dcs.isEmpty(), "No DCs available for
request (primary=%s, all disabled?)", primary);
+
+ Set<String> dcSet = new HashSet<>(dcs);
+ this.fullLayout = filterLayout(fullLayout, rp ->
dcSet.contains(metadata.locator.location(rp.endpoint()).datacenter));
+ this.liveLayout = filterLayout(this.fullLayout,
FailureDetector.isReplicaAlive);
+
+ this.fullLayouts = Maps.newHashMapWithExpectedSize(dcs.size());
+ this.liveLayouts = Maps.newHashMapWithExpectedSize(dcs.size());
+
+ this.fullEndpoints = Maps.newHashMapWithExpectedSize(dcs.size());
+ this.liveEndpoints = Maps.newHashMapWithExpectedSize(dcs.size());
+
+ populateDcLayouts();
+ }
+
+ AbstractReplicationStrategy strategy(ClusterMetadata metadata)
+ {
+ return
metadata.schema.getKeyspaceMetadata(keyspace.getName()).replicationStrategy;
+ }
+
+ List<String> createDcList()
+ {
+ List<String> results = new ArrayList<>();
+ if (!strategy.disabledDCs.contains(primary))
Review Comment:
This can happen during failover. During failover, you need to read from 2
intersecting sets of DCs. A QoQ of DCs from the old primary and the QoQ of DCs
from the new primary (so full DCs + satellite for primary for both
configurations). It's not possible to have an active primary that's disabled,
so the case where we're only returning satellites would be when we're failing
over. In that case we still need to include the satellite in read operations to
maintain correctness.
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