From 6c4ab0312b9829f5cb3db0480406fe79f0125f5e Mon Sep 17 00:00:00 2001 From: Weiwei Yang Date: Fri, 22 Feb 2019 00:18:07 +0800 Subject: [PATCH] YARN-9258. Support to specify allocation tags without constraint in distributed shell CLI. Contributed by Prabhu Joseph. --- .../constraint/PlacementConstraintParser.java | 74 ++++++++++------- .../TestPlacementConstraintParser.java | 79 ++++++++++++++----- .../distributedshell/PlacementSpec.java | 8 +- .../TestDSWithMultipleNodeManager.java | 6 +- .../site/markdown/PlacementConstraints.md.vm | 39 ++++----- 5 files changed, 134 insertions(+), 72 deletions(-) diff --git a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-api/src/main/java/org/apache/hadoop/yarn/util/constraint/PlacementConstraintParser.java b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-api/src/main/java/org/apache/hadoop/yarn/util/constraint/PlacementConstraintParser.java index db7c8b502e..0a28887b90 100644 --- a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-api/src/main/java/org/apache/hadoop/yarn/util/constraint/PlacementConstraintParser.java +++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-api/src/main/java/org/apache/hadoop/yarn/util/constraint/PlacementConstraintParser.java @@ -255,7 +255,7 @@ public String nextElement() { /** * Tokenizer used to parse allocation tags expression, which should be - * in tag=numOfAllocations syntax. + * in tag(numOfAllocations) syntax. */ public static class SourceTagsTokenizer implements ConstraintTokenizer { @@ -264,22 +264,24 @@ public static class SourceTagsTokenizer implements ConstraintTokenizer { private Iterator iterator; public SourceTagsTokenizer(String expr) { this.expression = expr; - st = new StringTokenizer(expr, String.valueOf(KV_SPLIT_DELIM)); + st = new StringTokenizer(expr, String.valueOf(BRACKET_START)); } @Override public void validate() throws PlacementConstraintParseException { ArrayList parsedValues = new ArrayList<>(); - if (st.countTokens() != 2) { + if (st.countTokens() != 2 || !this.expression. + endsWith(String.valueOf(BRACKET_END))) { throw new PlacementConstraintParseException( "Expecting source allocation tag to be specified" - + " sourceTag=numOfAllocations syntax," - + " but met " + expression); + + " sourceTag(numOfAllocations) syntax," + + " but met " + expression); } String sourceTag = st.nextToken(); parsedValues.add(sourceTag); - String num = st.nextToken(); + String str = st.nextToken(); + String num = str.substring(0, str.length() - 1); try { Integer.parseInt(num); parsedValues.add(num); @@ -630,7 +632,7 @@ public int getNumOfAllocations() { } /** - * Parses source tags from expression "sourceTags=numOfAllocations". + * Parses source tags from expression "sourceTags(numOfAllocations)". * @param expr * @return source tags, see {@link SourceTags} * @throws PlacementConstraintParseException @@ -690,12 +692,14 @@ public static AbstractConstraint parseExpression(String constraintStr) * is a composite expression which is composed by multiple sub constraint * expressions delimited by ":". With following syntax: * - *

Tag1=N1,P1:Tag2=N2,P2:...:TagN=Nn,Pn

+ *

Tag1(N1),P1:Tag2(N2),P2:...:TagN(Nn),Pn

* - * where TagN=Nn is a key value pair to determine the source + * where TagN(Nn) is a key value pair to determine the source * allocation tag and the number of allocations, such as: * - *

foo=3

+ *

foo(3)

+ * + * Optional when using NodeAttribute Constraint. * * and where Pn can be any form of a valid constraint expression, * such as: @@ -705,6 +709,13 @@ public static AbstractConstraint parseExpression(String constraintStr) *
  • notin,node,foo,bar,1,2
    • *
  • and(notin,node,foo:notin,node,bar)
    • * + * + * and NodeAttribute Constraint such as + * + *
      + *
    • yarn.rm.io/foo=true
      • + *
    • java=1.7,1.8
      • + *
    * @param expression expression string. * @return a map of source tags to placement constraint mapping. * @throws PlacementConstraintParseException @@ -719,30 +730,35 @@ public static Map parsePlacementSpec( tokenizer.validate(); while (tokenizer.hasMoreElements()) { String specStr = tokenizer.nextElement(); - // each spec starts with sourceAllocationTag=numOfContainers and + // each spec starts with sourceAllocationTag(numOfContainers) and // followed by a constraint expression. - // foo=4,Pn - String[] splitted = specStr.split( - String.valueOf(EXPRESSION_VAL_DELIM), 2); + // foo(4),Pn final SourceTags st; - final String exprs; - if (splitted.length == 1) { - // source tags not specified - exprs = splitted[0]; - st = SourceTags.emptySourceTags(); - } else if (splitted.length == 2) { - exprs = splitted[1]; - String tagAlloc = splitted[0]; - st = SourceTags.parseFrom(tagAlloc); + PlacementConstraint constraint; + String delimiter = new String(new char[]{'[', BRACKET_END, ']', + EXPRESSION_VAL_DELIM}); + String[] splitted = specStr.split(delimiter, 2); + if (splitted.length == 2) { + st = SourceTags.parseFrom(splitted[0] + String.valueOf(BRACKET_END)); + constraint = PlacementConstraintParser.parseExpression(splitted[1]). + build(); + } else if (splitted.length == 1) { + // Either Node Attribute Constraint or Source Allocation Tag alone + NodeConstraintParser np = new NodeConstraintParser(specStr); + Optional constraintOptional = + Optional.ofNullable(np.tryParse()); + if (constraintOptional.isPresent()) { + st = SourceTags.emptySourceTags(); + constraint = constraintOptional.get().build(); + } else { + st = SourceTags.parseFrom(specStr); + constraint = null; + } } else { throw new PlacementConstraintParseException( "Unexpected placement constraint expression " + specStr); } - - AbstractConstraint constraint = - PlacementConstraintParser.parseExpression(exprs); - - result.put(st, constraint.build()); + result.put(st, constraint); } // Validation @@ -751,7 +767,7 @@ public static Map parsePlacementSpec( .filter(sourceTags -> sourceTags.isEmpty()) .findAny() .isPresent()) { - // Source tags, e.g foo=3, is optional for a node-attribute constraint, + // Source tags, e.g foo(3), is optional for a node-attribute constraint, // but when source tags is absent, the parser only accept single // constraint expression to avoid ambiguous semantic. This is because // DS AM is requesting number of containers per the number specified diff --git a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-api/src/test/java/org/apache/hadoop/yarn/api/resource/TestPlacementConstraintParser.java b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-api/src/test/java/org/apache/hadoop/yarn/api/resource/TestPlacementConstraintParser.java index f5fbc2632a..d4b330c8ff 100644 --- a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-api/src/test/java/org/apache/hadoop/yarn/api/resource/TestPlacementConstraintParser.java +++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-api/src/test/java/org/apache/hadoop/yarn/api/resource/TestPlacementConstraintParser.java @@ -22,6 +22,7 @@ import java.util.Iterator; import java.util.Map; import java.util.Set; +import java.util.TreeSet; import org.apache.hadoop.yarn.api.records.NodeAttributeOpCode; import org.apache.hadoop.yarn.api.resource.PlacementConstraint.AbstractConstraint; @@ -274,15 +275,15 @@ public void testMultipleConstraintsTokenizer() TokenizerTester mp; ct = new MultipleConstraintsTokenizer( - "foo=1,A1,A2,A3:bar=2,B1,B2:moo=3,C1,C2"); + "foo(1),A1,A2,A3:bar(2),B1,B2:moo(3),C1,C2"); mp = new TokenizerTester(ct, - "foo=1,A1,A2,A3", "bar=2,B1,B2", "moo=3,C1,C2"); + "foo(1),A1,A2,A3", "bar(2),B1,B2", "moo(3),C1,C2"); mp.verify(); ct = new MultipleConstraintsTokenizer( - "foo=1,AND(A2:A3):bar=2,OR(B1:AND(B2:B3)):moo=3,C1,C2"); + "foo(1),AND(A2:A3):bar(2),OR(B1:AND(B2:B3)):moo(3),C1,C2"); mp = new TokenizerTester(ct, - "foo=1,AND(A2:A3)", "bar=2,OR(B1:AND(B2:B3))", "moo=3,C1,C2"); + "foo(1),AND(A2:A3)", "bar(2),OR(B1:AND(B2:B3))", "moo(3),C1,C2"); mp.verify(); ct = new MultipleConstraintsTokenizer("A:B:C"); @@ -301,12 +302,12 @@ public void testMultipleConstraintsTokenizer() mp = new TokenizerTester(ct, "A", "AND(B:OR(C:D))", "E"); mp.verify(); - st = new SourceTagsTokenizer("A=4"); + st = new SourceTagsTokenizer("A(4)"); mp = new TokenizerTester(st, "A", "4"); mp.verify(); try { - st = new SourceTagsTokenizer("A=B"); + st = new SourceTagsTokenizer("A(B)"); mp = new TokenizerTester(st, "A", "B"); mp.verify(); Assert.fail("Expecting a parsing failure"); @@ -348,9 +349,20 @@ public void testParsePlacementSpec() PlacementConstraint actualPc1, actualPc2; SourceTags tag1, tag2; + // Only Source Tag without constraint + result = PlacementConstraintParser + .parsePlacementSpec("foo(3)"); + Assert.assertEquals(1, result.size()); + tag1 = result.keySet().iterator().next(); + Assert.assertEquals("foo", tag1.getTag()); + Assert.assertEquals(3, tag1.getNumOfAllocations()); + expectedPc1 = null; + actualPc1 = result.values().iterator().next(); + Assert.assertEquals(expectedPc1, actualPc1); + // A single anti-affinity constraint result = PlacementConstraintParser - .parsePlacementSpec("foo=3,notin,node,foo"); + .parsePlacementSpec("foo(3),notin,node,foo"); Assert.assertEquals(1, result.size()); tag1 = result.keySet().iterator().next(); Assert.assertEquals("foo", tag1.getTag()); @@ -361,7 +373,7 @@ public void testParsePlacementSpec() // Upper case result = PlacementConstraintParser - .parsePlacementSpec("foo=3,NOTIN,NODE,foo"); + .parsePlacementSpec("foo(3),NOTIN,NODE,foo"); Assert.assertEquals(1, result.size()); tag1 = result.keySet().iterator().next(); Assert.assertEquals("foo", tag1.getTag()); @@ -372,7 +384,7 @@ public void testParsePlacementSpec() // A single cardinality constraint result = PlacementConstraintParser - .parsePlacementSpec("foo=10,cardinality,node,foo,bar,0,100"); + .parsePlacementSpec("foo(10),cardinality,node,foo,bar,0,100"); Assert.assertEquals(1, result.size()); tag1 = result.keySet().iterator().next(); Assert.assertEquals("foo", tag1.getTag()); @@ -386,7 +398,7 @@ public void testParsePlacementSpec() // Two constraint expressions result = PlacementConstraintParser - .parsePlacementSpec("foo=3,notin,node,foo:bar=2,in,node,foo"); + .parsePlacementSpec("foo(3),notin,node,foo:bar(2),in,node,foo"); Assert.assertEquals(2, result.size()); Iterator keyIt = result.keySet().iterator(); tag1 = keyIt.next(); @@ -403,7 +415,7 @@ public void testParsePlacementSpec() // And constraint result = PlacementConstraintParser - .parsePlacementSpec("foo=1000,and(notin,node,bar:in,node,foo)"); + .parsePlacementSpec("foo(1000),and(notin,node,bar:in,node,foo)"); Assert.assertEquals(1, result.size()); keyIt = result.keySet().iterator(); tag1 = keyIt.next(); @@ -416,8 +428,8 @@ public void testParsePlacementSpec() // Multiple constraints with nested forms. result = PlacementConstraintParser.parsePlacementSpec( - "foo=1000,and(notin,node,bar:or(in,node,foo:in,node,moo))" - + ":bar=200,notin,node,foo"); + "foo(1000),and(notin,node,bar:or(in,node,foo:in,node,moo))" + + ":bar(200),notin,node,foo"); Assert.assertEquals(2, result.size()); keyIt = result.keySet().iterator(); tag1 = keyIt.next(); @@ -436,6 +448,17 @@ public void testParsePlacementSpec() Assert.assertEquals(actualPc1, expectedPc1); expectedPc2 = targetNotIn("node", allocationTag("foo")).build(); Assert.assertEquals(expectedPc2, actualPc2); + + // Failure Cases + String[] invalidSpecs = {"foo(3", "foo),bar", "foobar", "),java=1.7,1.8"}; + for (String spec : invalidSpecs) { + try { + result = PlacementConstraintParser.parsePlacementSpec(spec); + Assert.fail("Expected a failure!"); + } catch (Exception e) { + Assert.assertTrue(e instanceof PlacementConstraintParseException); + } + } } // We verify the toString result by parsing it again @@ -466,7 +489,7 @@ public void testParseNodeAttributeSpec() // A single node attribute constraint result = PlacementConstraintParser - .parsePlacementSpec("xyz=4,rm.yarn.io/foo=true"); + .parsePlacementSpec("xyz(4),rm.yarn.io/foo=true"); Assert.assertEquals(1, result.size()); TargetExpression target = PlacementTargets .nodeAttribute("rm.yarn.io/foo", "true"); @@ -477,7 +500,7 @@ public void testParseNodeAttributeSpec() // A single node attribute constraint result = PlacementConstraintParser - .parsePlacementSpec("xyz=3,rm.yarn.io/foo!=abc"); + .parsePlacementSpec("xyz(3),rm.yarn.io/foo!=abc"); Assert.assertEquals(1, result.size()); target = PlacementTargets .nodeAttribute("rm.yarn.io/foo", "abc"); @@ -492,7 +515,7 @@ public void testParseNodeAttributeSpec() // A single node attribute constraint result = PlacementConstraintParser .parsePlacementSpec( - "xyz=1,rm.yarn.io/foo!=abc:zxy=1,rm.yarn.io/bar=true"); + "xyz(1),rm.yarn.io/foo!=abc:zxy(1),rm.yarn.io/bar=true"); Assert.assertEquals(2, result.size()); target = PlacementTargets .nodeAttribute("rm.yarn.io/foo", "abc"); @@ -519,11 +542,27 @@ public void testParseNodeAttributeSpec() actualPc1 = result.values().iterator().next(); Assert.assertEquals(expectedPc1, actualPc1.getConstraintExpr()); + // Node Attribute Constraint With Multiple Values + result = PlacementConstraintParser + .parsePlacementSpec("java=1.7,1.8"); + Assert.assertEquals(1, result.size()); + + Set constraintEntities = new TreeSet<>(); + constraintEntities.add("1.7"); + constraintEntities.add("1.8"); + target = PlacementConstraints.PlacementTargets.nodeAttribute("java", + constraintEntities.toArray(new String[constraintEntities.size()])); + expectedPc1 = targetNodeAttribute("node", NodeAttributeOpCode.EQ, target); + actualSourceTags = result.keySet().iterator().next(); + Assert.assertTrue(actualSourceTags.isEmpty()); + actualPc1 = result.values().iterator().next(); + Assert.assertEquals(expectedPc1, actualPc1.getConstraintExpr()); + // If source tags is not specified for a node-attribute constraint, // then this expression must be single constraint expression. try { PlacementConstraintParser - .parsePlacementSpec("rm.yarn.io/foo=true:xyz=1,notin,node,xyz"); + .parsePlacementSpec("rm.yarn.io/foo=true:xyz(1),notin,node,xyz"); Assert.fail("Expected a failure!"); } catch (Exception e) { Assert.assertTrue(e instanceof PlacementConstraintParseException); @@ -537,7 +576,7 @@ public void testParseAllocationTagNameSpace() // Constraint with Two Different NameSpaces result = PlacementConstraintParser - .parsePlacementSpec("foo=2,notin,node,not-self/bar,all/moo"); + .parsePlacementSpec("foo(2),notin,node,not-self/bar,all/moo"); Assert.assertEquals(1, result.size()); Set expectedTargetExpressions = Sets.newHashSet( PlacementTargets.allocationTagWithNamespace("not-self", "bar"), @@ -552,7 +591,7 @@ public void testParseAllocationTagNameSpace() // Constraint With Default NameSpace SELF result = PlacementConstraintParser - .parsePlacementSpec("foo=2,notin,node,moo"); + .parsePlacementSpec("foo(2),notin,node,moo"); Assert.assertEquals(1, result.size()); TargetExpression expectedTargetExpression = PlacementTargets. allocationTagWithNamespace("self", "moo"); @@ -567,7 +606,7 @@ public void testParseAllocationTagNameSpace() boolean caughtException = false; try { result = PlacementConstraintParser - .parsePlacementSpec("foo=2,notin,node,bar/moo"); + .parsePlacementSpec("foo(2),notin,node,bar/moo"); } catch(PlacementConstraintParseException e) { caughtException = true; } diff --git a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-applications/hadoop-yarn-applications-distributedshell/src/main/java/org/apache/hadoop/yarn/applications/distributedshell/PlacementSpec.java b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-applications/hadoop-yarn-applications-distributedshell/src/main/java/org/apache/hadoop/yarn/applications/distributedshell/PlacementSpec.java index ceaa37d587..7c6daf6d21 100644 --- a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-applications/hadoop-yarn-applications-distributedshell/src/main/java/org/apache/hadoop/yarn/applications/distributedshell/PlacementSpec.java +++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-applications/hadoop-yarn-applications-distributedshell/src/main/java/org/apache/hadoop/yarn/applications/distributedshell/PlacementSpec.java @@ -96,8 +96,12 @@ public static Map parse(String specs) parsed.entrySet()) { LOG.info("Parsed source tag: {}, number of allocations: {}", entry.getKey().getTag(), entry.getKey().getNumOfAllocations()); - LOG.info("Parsed constraint: {}", entry.getValue() - .getConstraintExpr().getClass().getSimpleName()); + if (entry.getValue() != null) { + LOG.info("Parsed constraint: {}", entry.getValue() + .getConstraintExpr().getClass().getSimpleName()); + } else { + LOG.info("Parsed constraint Empty"); + } pSpecs.put(entry.getKey().getTag(), new PlacementSpec( entry.getKey().getTag(), entry.getKey().getNumOfAllocations(), diff --git a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-applications/hadoop-yarn-applications-distributedshell/src/test/java/org/apache/hadoop/yarn/applications/distributedshell/TestDSWithMultipleNodeManager.java b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-applications/hadoop-yarn-applications-distributedshell/src/test/java/org/apache/hadoop/yarn/applications/distributedshell/TestDSWithMultipleNodeManager.java index 7b940c881a..f3571a6b81 100644 --- a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-applications/hadoop-yarn-applications-distributedshell/src/test/java/org/apache/hadoop/yarn/applications/distributedshell/TestDSWithMultipleNodeManager.java +++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-applications/hadoop-yarn-applications-distributedshell/src/test/java/org/apache/hadoop/yarn/applications/distributedshell/TestDSWithMultipleNodeManager.java @@ -156,7 +156,7 @@ public void testDistributedShellWithPlacementConstraint() "--shell_command", distShellTest.getSleepCommand(15), "--placement_spec", - "zk=1,NOTIN,NODE,zk:spark=1,NOTIN,NODE,zk" + "zk(1),NOTIN,NODE,zk:spark(1),NOTIN,NODE,zk" }; LOG.info("Initializing DS Client"); final Client client = @@ -202,7 +202,7 @@ public void testDistributedShellWithAllocationTagNamespace() "--shell_command", distShellTest.getSleepCommand(30), "--placement_spec", - "bar=1,notin,node,bar" + "bar(1),notin,node,bar" }; final Client clientA = new Client(new Configuration(distShellTest.yarnCluster.getConfig())); @@ -275,7 +275,7 @@ public void run() { "--shell_command", Shell.WINDOWS ? "dir" : "ls", "--placement_spec", - "foo=3,notin,node,all/bar" + "foo(3),notin,node,all/bar" }; final Client clientB = new Client(new Configuration(distShellTest. yarnCluster.getConfig())); diff --git a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-site/src/site/markdown/PlacementConstraints.md.vm b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-site/src/site/markdown/PlacementConstraints.md.vm index 598d997624..c212a9d7f5 100644 --- a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-site/src/site/markdown/PlacementConstraints.md.vm +++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-site/src/site/markdown/PlacementConstraints.md.vm @@ -65,26 +65,29 @@ $ yarn org.apache.hadoop.yarn.applications.distributedshell.Client -jar share/ha where **PlacementSpec** is of the form: ``` -PlacementSpec => "" | KeyVal;PlacementSpec -KeyVal => SourceTag=ConstraintExpr -SourceTag => String -ConstraintExpr => NumContainers | NumContainers, Constraint -Constraint => SingleConstraint | CompositeConstraint -SingleConstraint => "IN",Scope,TargetTag | "NOTIN",Scope,TargetTag | "CARDINALITY",Scope,TargetTag,MinCard,MaxCard -CompositeConstraint => AND(ConstraintList) | OR(ConstraintList) -ConstraintList => Constraint | Constraint:ConstraintList -NumContainers => int -Scope => "NODE" | "RACK" -TargetTag => String -MinCard => int -MaxCard => int +PlacementSpec => "" | PlacementExpr;PlacementSpec +PlacementExpr => SourceTag,ConstraintExpr +SourceTag => String(NumContainers) +ConstraintExpr => SingleConstraint | CompositeConstraint +SingleConstraint => "IN",Scope,TargetTag | "NOTIN",Scope,TargetTag | "CARDINALITY",Scope,TargetTag,MinCard,MaxCard | NodeAttributeConstraintExpr +NodeAttributeConstraintExpr => NodeAttributeName=Value, NodeAttributeName!=Value +CompositeConstraint => AND(ConstraintList) | OR(ConstraintList) +ConstraintList => Constraint | Constraint:ConstraintList +NumContainers => int +Scope => "NODE" | "RACK" +TargetTag => String +MinCard => int +MaxCard => int ``` -Note that when the `-placement_spec` argument is specified in the distributed shell command, the `-num-containers` argument should not be used. In case `-num-containers` argument is used in conjunction with `-placement-spec`, the former is ignored. This is because in PlacementSpec, we determine the number of containers per tag, making the `-num-containers` redundant and possibly conflicting. Moreover, if `-placement_spec` is used, all containers will be requested with GUARANTEED execution type. +Note: + +* When the `-placement_spec` argument is specified (except NodeAttributeConstraintExpr) in the distributed shell command, the `-num-containers` argument should not be used. In case `-num-containers` argument is used in conjunction with `-placement-spec`, the former is ignored. This is because in PlacementSpec, we determine the number of containers per tag, making the `-num-containers` redundant and possibly conflicting. Moreover, if `-placement_spec` is used, all containers will be requested with GUARANTEED execution type. +* When the `NodeAttributeConstraintExpr` is specified, `SourceTag(NumContainers)` is optional and the value of `-num-containers` will be considered for the number of containers to request. An example of PlacementSpec is the following: ``` -zk=3,NOTIN,NODE,zk:hbase=5,IN,RACK,zk:spark=7,CARDINALITY,NODE,hbase,1,3 +zk(3),NOTIN,NODE,zk:hbase(5),IN,RACK,zk:spark(7),CARDINALITY,NODE,hbase,1,3 ``` The above encodes three constraints: @@ -94,7 +97,7 @@ The above encodes three constraints: Another example below demonstrates a composite form of constraint: ``` -zk=5,AND(IN,RACK,hbase:NOTIN,NODE,zk) +zk(5),AND(IN,RACK,hbase:NOTIN,NODE,zk) ``` The above constraint uses the conjunction operator `AND` to combine two constraints. The AND constraint is satisfied when both its children constraints are satisfied. The specific PlacementSpec requests to place 5 "zk" containers in a rack where at least one "hbase" container is running, and on a node that no "zk" container is running. Similarly, an `OR` operator can be used to define a constraint that is satisfied when at least one of its children constraints is satisfied. @@ -130,7 +133,7 @@ To attach an allocation tag namespace `ns` to a target tag `targetTag`, we use t The example constraints used above could be extended with namespaces as follows: ``` -zk=3,NOTIN,NODE,not-self/zk:hbase=5,IN,RACK,all/zk:spark=7,CARDINALITY,NODE,app-id/appID_0023/hbase,1,3 +zk(3),NOTIN,NODE,not-self/zk:hbase(5),IN,RACK,all/zk:spark(7),CARDINALITY,NODE,app-id/appID_0023/hbase,1,3 ``` The semantics of these constraints are the following: @@ -175,4 +178,4 @@ Applications have to specify the containers for which each constraint will be en When using the `placement-processor` handler (see [Enabling placement constraints](#Enabling_placement_constraints)), this constraint mapping is specified within the `RegisterApplicationMasterRequest`. -When using the `scheduler` handler, the constraints can also be added at each `SchedulingRequest` object. Each such constraint is valid for the tag of that scheduling request. In case constraints are specified both at the `RegisterApplicationMasterRequest` and the scheduling requests, the latter override the former. \ No newline at end of file +When using the `scheduler` handler, the constraints can also be added at each `SchedulingRequest` object. Each such constraint is valid for the tag of that scheduling request. In case constraints are specified both at the `RegisterApplicationMasterRequest` and the scheduling requests, the latter override the former.