org.apache.hadoop.hive.ql.optimizer.TablePropertyEnrichmentOptimizer Maven / Gradle / Ivy
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* to you under the Apache License, Version 2.0 (the
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package org.apache.hadoop.hive.ql.optimizer;
import com.google.common.collect.Lists;
import com.google.common.collect.Maps;
import com.google.common.collect.Sets;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hive.conf.HiveConf;
import org.apache.hadoop.hive.metastore.api.Table;
import org.apache.hadoop.hive.metastore.utils.MetaStoreUtils;
import org.apache.hadoop.hive.ql.exec.TableScanOperator;
import org.apache.hadoop.hive.ql.lib.DefaultRuleDispatcher;
import org.apache.hadoop.hive.ql.lib.Dispatcher;
import org.apache.hadoop.hive.ql.lib.GraphWalker;
import org.apache.hadoop.hive.ql.lib.Node;
import org.apache.hadoop.hive.ql.lib.NodeProcessor;
import org.apache.hadoop.hive.ql.lib.NodeProcessorCtx;
import org.apache.hadoop.hive.ql.lib.PreOrderWalker;
import org.apache.hadoop.hive.ql.lib.Rule;
import org.apache.hadoop.hive.ql.lib.RuleRegExp;
import org.apache.hadoop.hive.ql.parse.ParseContext;
import org.apache.hadoop.hive.ql.parse.SemanticException;
import org.apache.hadoop.hive.ql.plan.TableScanDesc;
import org.apache.hadoop.hive.serde2.Deserializer;
import org.apache.hive.common.util.ReflectionUtil;
import java.util.Arrays;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Properties;
import java.util.Set;
import java.util.Stack;
/**
* Optimizer that updates TableScanOperators' Table-references with properties that might be
* updated/pre-fetched by initializing the table's SerDe.
* E.g. AvroSerDes can now prefetch schemas from schema-urls and update the table-properties directly.
*/
class TablePropertyEnrichmentOptimizer extends Transform {
private static Log LOG = LogFactory.getLog(TablePropertyEnrichmentOptimizer.class);
private static class WalkerCtx implements NodeProcessorCtx {
Configuration conf;
Set serdeClassesUnderConsideration = Sets.newHashSet();
WalkerCtx(Configuration conf) {
this.conf = conf;
serdeClassesUnderConsideration.addAll(
Arrays.asList( HiveConf.getVar(conf,
HiveConf.ConfVars.HIVE_OPTIMIZE_TABLE_PROPERTIES_FROM_SERDE_LIST)
.split(",")));
if (LOG.isDebugEnabled()) {
LOG.debug("TablePropertyEnrichmentOptimizer considers these SerDe classes:");
for (String className : serdeClassesUnderConsideration) {
LOG.debug(className);
}
}
}
}
/**
* Retrieves the table properties as well as the properties from Serde.
*/
private static Map getTableParameters(Table table) {
Map originalTableParameters = new HashMap<>(table.getParameters());
Properties tableMetadata = MetaStoreUtils.getTableMetadata(table);
for (String property : tableMetadata.stringPropertyNames()) {
if (!originalTableParameters.containsKey(property)) {
originalTableParameters.put(property, tableMetadata.getProperty(property));
}
}
return originalTableParameters;
}
private static class Processor implements NodeProcessor {
@Override
public Object process(Node nd, Stack stack, NodeProcessorCtx procCtx, Object... nodeOutputs) throws SemanticException {
TableScanOperator tsOp = (TableScanOperator) nd;
WalkerCtx context = (WalkerCtx)procCtx;
TableScanDesc tableScanDesc = tsOp.getConf();
Table table = tsOp.getConf().getTableMetadata().getTTable();
Map originalTableParameters = getTableParameters(table);
if (LOG.isDebugEnabled()) {
LOG.debug("Original Table parameters: " + originalTableParameters);
}
Properties clonedTableParameters = new Properties();
clonedTableParameters.putAll(originalTableParameters);
String deserializerClassName = null;
try {
deserializerClassName = tableScanDesc.getTableMetadata().getSd().getSerdeInfo().getSerializationLib();
Deserializer deserializer = ReflectionUtil.newInstance(
context.conf.getClassByName(deserializerClassName)
.asSubclass(Deserializer.class),
context.conf);
if (context.serdeClassesUnderConsideration.contains(deserializerClassName)) {
deserializer.initialize(context.conf, clonedTableParameters);
LOG.debug("SerDe init succeeded for class: " + deserializerClassName);
for (Map.Entry property : clonedTableParameters.entrySet()) {
if (!property.getValue().equals(originalTableParameters.get(property.getKey()))) {
LOG.debug("Resolving changed parameters! key=" + property.getKey() + ", value=" + property.getValue());
table.getParameters().put((String) property.getKey(), (String) property.getValue());
}
}
}
else {
if (LOG.isDebugEnabled()) {
LOG.debug("Skipping prefetch for " + deserializerClassName);
}
}
}
catch(Throwable t) {
LOG.error("SerDe init failed for SerDe class==" + deserializerClassName
+ ". Didn't change table-properties", t);
}
return nd;
}
}
@Override
public ParseContext transform(ParseContext pctx) throws SemanticException {
LOG.info("TablePropertyEnrichmentOptimizer::transform().");
Map opRules = Maps.newLinkedHashMap();
opRules.put(new RuleRegExp("R1", TableScanOperator.getOperatorName() + "%"),
new Processor());
WalkerCtx context = new WalkerCtx(pctx.getConf());
Dispatcher disp = new DefaultRuleDispatcher(null, opRules, context);
List topNodes = Lists.newArrayList();
topNodes.addAll(pctx.getTopOps().values());
GraphWalker walker = new PreOrderWalker(disp);
walker.startWalking(topNodes, null);
LOG.info("TablePropertyEnrichmentOptimizer::transform() complete!");
return pctx;
}
}