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https://issues.apache.org/jira/browse/BEAM-9008?focusedWorklogId=419003&page=com.atlassian.jira.plugin.system.issuetabpanels:worklog-tabpanel#worklog-419003
]
ASF GitHub Bot logged work on BEAM-9008:
----------------------------------------
Author: ASF GitHub Bot
Created on: 08/Apr/20 23:54
Start Date: 08/Apr/20 23:54
Worklog Time Spent: 10m
Work Description: vmarquez commented on pull request #10546: [BEAM-9008]
Add CassandraIO readAll method
URL: https://github.com/apache/beam/pull/10546#discussion_r405880091
##########
File path:
sdks/java/io/cassandra/src/main/java/org/apache/beam/sdk/io/cassandra/CassandraIO.java
##########
@@ -1170,4 +887,344 @@ private void waitForFuturesToFinish() throws
ExecutionException, InterruptedExce
}
}
}
+
+ /**
+ * A {@link PTransform} to read data from Apache Cassandra. See {@link
CassandraIO} for more
+ * information on usage and configuration.
+ */
+ @AutoValue
+ public abstract static class ReadAll<T> extends
PTransform<PCollection<Read<T>>, PCollection<T>> {
+
+ @Nullable
+ abstract ValueProvider<List<String>> hosts();
+
+ @Nullable
+ abstract ValueProvider<String> query();
+
+ @Nullable
+ abstract ValueProvider<Integer> port();
+
+ @Nullable
+ abstract ValueProvider<String> keyspace();
+
+ @Nullable
+ abstract ValueProvider<String> table();
+
+ @Nullable
+ abstract Class<T> entity();
+
+ @Nullable
+ abstract Coder<T> coder();
+
+ @Nullable
+ abstract ValueProvider<String> username();
+
+ @Nullable
+ abstract ValueProvider<String> password();
+
+ @Nullable
+ abstract ValueProvider<String> localDc();
+
+ @Nullable
+ abstract ValueProvider<String> consistencyLevel();
+
+ @Nullable
+ abstract ValueProvider<Integer> splitCount();
+
+ @Nullable
+ abstract SerializableFunction<Session, Mapper> mapperFactoryFn();
+
+ @Nullable
+ abstract SerializableFunction<RingRange, Integer> groupingFn();
+
+ abstract Builder<T> builder();
+
+ /** Specify the hosts of the Apache Cassandra instances. */
+ public ReadAll<T> withHosts(List<String> hosts) {
+ checkArgument(hosts != null, "hosts can not be null");
+ checkArgument(!hosts.isEmpty(), "hosts can not be empty");
+ return withHosts(ValueProvider.StaticValueProvider.of(hosts));
+ }
+
+ /** Specify the hosts of the Apache Cassandra instances. */
+ public ReadAll<T> withHosts(ValueProvider<List<String>> hosts) {
+ return builder().setHosts(hosts).build();
+ }
+
+ /** Specify the port number of the Apache Cassandra instances. */
+ public ReadAll<T> withPort(int port) {
+ checkArgument(port > 0, "port must be > 0, but was: %s", port);
+ return withPort(ValueProvider.StaticValueProvider.of(port));
+ }
+
+ /** Specify the port number of the Apache Cassandra instances. */
+ public ReadAll<T> withPort(ValueProvider<Integer> port) {
+ return builder().setPort(port).build();
+ }
+
+ /** Specify the Cassandra keyspace where to read data. */
+ public ReadAll<T> withKeyspace(String keyspace) {
+ checkArgument(keyspace != null, "keyspace can not be null");
+ return withKeyspace(ValueProvider.StaticValueProvider.of(keyspace));
+ }
+
+ /** Specify the Cassandra keyspace where to read data. */
+ public ReadAll<T> withKeyspace(ValueProvider<String> keyspace) {
+ return builder().setKeyspace(keyspace).build();
+ }
+
+ /** Specify the Cassandra table where to read data. */
+ public ReadAll<T> withTable(String table) {
+ checkArgument(table != null, "table can not be null");
+ return withTable(ValueProvider.StaticValueProvider.of(table));
+ }
+
+ /** Specify the Cassandra table where to read data. */
+ public ReadAll<T> withTable(ValueProvider<String> table) {
+ return builder().setTable(table).build();
+ }
+
+ /** Specify the query to read data. */
+ public ReadAll<T> withQuery(String query) {
+ checkArgument(query != null && query.length() > 0, "query cannot be
null");
+ return withQuery(ValueProvider.StaticValueProvider.of(query));
+ }
+
+ /** Specify the query to read data. */
+ public ReadAll<T> withQuery(ValueProvider<String> query) {
+ return builder().setQuery(query).build();
+ }
+
+ /**
+ * Specify the entity class (annotated POJO). The {@link CassandraIO} will
read the data and
+ * convert the data as entity instances. The {@link PCollection} resulting
from the read will
+ * contains entity elements.
+ */
+ public ReadAll<T> withEntity(Class<T> entity) {
+ checkArgument(entity != null, "entity can not be null");
+ return builder().setEntity(entity).build();
+ }
+
+ /** Specify the {@link Coder} used to serialize the entity in the {@link
PCollection}. */
+ public ReadAll<T> withCoder(Coder<T> coder) {
+ checkArgument(coder != null, "coder can not be null");
+ return builder().setCoder(coder).build();
+ }
+
+ /** Specify the username for authentication. */
+ public ReadAll<T> withUsername(String username) {
+ checkArgument(username != null, "username can not be null");
+ return withUsername(ValueProvider.StaticValueProvider.of(username));
+ }
+
+ /** Specify the username for authentication. */
+ public ReadAll<T> withUsername(ValueProvider<String> username) {
+ return builder().setUsername(username).build();
+ }
+
+ /** Specify the password used for authentication. */
+ public ReadAll<T> withPassword(String password) {
+ checkArgument(password != null, "password can not be null");
+ return withPassword(ValueProvider.StaticValueProvider.of(password));
+ }
+
+ /** Specify the password used for authentication. */
+ public ReadAll<T> withPassword(ValueProvider<String> password) {
+ return builder().setPassword(password).build();
+ }
+
+ /** Specify the local DC used for the load balancing. */
+ public ReadAll<T> withLocalDc(String localDc) {
+ checkArgument(localDc != null, "localDc can not be null");
+ return withLocalDc(ValueProvider.StaticValueProvider.of(localDc));
+ }
+
+ /** Specify the local DC used for the load balancing. */
+ public ReadAll<T> withLocalDc(ValueProvider<String> localDc) {
+ return builder().setLocalDc(localDc).build();
+ }
+
+ public ReadAll<T> withConsistencyLevel(String consistencyLevel) {
+ checkArgument(consistencyLevel != null, "consistencyLevel can not be
null");
+ return
withConsistencyLevel(ValueProvider.StaticValueProvider.of(consistencyLevel));
+ }
+
+ public ReadAll<T> withConsistencyLevel(ValueProvider<String>
consistencyLevel) {
+ return builder().setConsistencyLevel(consistencyLevel).build();
+ }
+
+ public ReadAll<T> withGroupingFn(SerializableFunction<RingRange, Integer>
groupingFunction) {
+ return builder().setGroupingFn(groupingFunction).build();
+ }
+
+ public ReadAll<T> withSplitCount(ValueProvider<Integer> splitCount) {
+ return builder().setSplitCount(splitCount).build();
+ }
+
+ public ReadAll<T> withSplitCount(Integer splitCount) {
+ checkArgument(splitCount != null, "splitCount can not be null");
+ return
withSplitCount(ValueProvider.StaticValueProvider.<Integer>of(splitCount));
+ }
+
+ /**
+ * A factory to create a specific {@link Mapper} for a given Cassandra
Session. This is useful
+ * to provide mappers that don't rely in Cassandra annotated objects.
+ */
+ public ReadAll<T> withMapperFactoryFn(SerializableFunction<Session,
Mapper> mapperFactory) {
+ checkArgument(
+ mapperFactory != null,
+ "CassandraIO.withMapperFactory" + "(withMapperFactory) called with
null value");
+ return builder().setMapperFactoryFn(mapperFactory).build();
+ }
+
+ @Override
+ public PCollection<T> expand(PCollection<Read<T>> input) {
+ checkArgument((hosts() != null && port() != null), "WithHosts() and
withPort() are required");
+ checkArgument(keyspace() != null, "withKeyspace() is required");
+ checkArgument(table() != null, "withTable() is required");
+ checkArgument(entity() != null, "withEntity() is required");
+ checkArgument(coder() != null, "withCoder() is required");
+ checkArgument(groupingFn() != null, "GroupingFn OR splitCount must be
set");
+ try (Cluster cluster =
Review comment:
Not sure I understand what you mean here. I'm doing a shuffle by key here,
`FlattenGrouped` here is what I called it, following the other connectors
general pattern.
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Issue Time Tracking
-------------------
Worklog Id: (was: 419003)
Time Spent: 9.5h (was: 9h 20m)
> Add readAll() method to CassandraIO
> -----------------------------------
>
> Key: BEAM-9008
> URL: https://issues.apache.org/jira/browse/BEAM-9008
> Project: Beam
> Issue Type: New Feature
> Components: io-java-cassandra
> Affects Versions: 2.16.0
> Reporter: vincent marquez
> Assignee: vincent marquez
> Priority: Minor
> Time Spent: 9.5h
> Remaining Estimate: 0h
>
> When querying a large cassandra database, it's often *much* more useful to
> programatically generate the queries needed to to be run rather than reading
> all partitions and attempting some filtering.
> As an example:
> {code:java}
> public class Event {
> @PartitionKey(0) public UUID accountId;
> @PartitionKey(1)public String yearMonthDay;
> @ClusteringKey public UUID eventId;
> //other data...
> }{code}
> If there is ten years worth of data, you may want to only query one year's
> worth. Here each token range would represent one 'token' but all events for
> the day.
> {code:java}
> Set<UUID> accounts = getRelevantAccounts();
> Set<String> dateRange = generateDateRange("2018-01-01", "2019-01-01");
> PCollection<TokenRange> tokens = generateTokens(accounts, dateRange);
> {code}
>
> I propose an additional _readAll()_ PTransform that can take a PCollection
> of token ranges and can return a PCollection<T> of what the query would
> return.
> *Question: How much code should be in common between both methods?*
> Currently the read connector already groups all partitions into a List of
> Token Ranges, so it would be simple to refactor the current read() based
> method to a 'ParDo' based one and have them both share the same function.
> Reasons against sharing code between read and readAll
> * Not having the read based method return a BoundedSource connector would
> mean losing the ability to know the size of the data returned
> * Currently the CassandraReader executes all the grouped TokenRange queries
> *asynchronously* which is (maybe?) fine when all that's happening is
> splitting up all the partition ranges but terrible for executing potentially
> millions of queries.
> Reasons _for_ sharing code would be simplified code base and that both of
> the above issues would most likely have a negligable performance impact.
>
>
>
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