HADOOP-9125. LdapGroupsMapping threw CommunicationException after some idle time. Contributed by Kai Zheng.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1461864 13f79535-47bb-0310-9956-ffa450edef68
This commit is contained in:
Aaron Myers 2013-03-27 21:52:52 +00:00
parent 701ef114fb
commit c427540ced
3 changed files with 105 additions and 41 deletions

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@ -95,6 +95,9 @@ Release 2.0.5-beta - UNRELEASED
HADOOP-9430. TestSSLFactory fails on IBM JVM. (Amir Sanjar via suresh)
HADOOP-9125. LdapGroupsMapping threw CommunicationException after some
idle time. (Kai Zheng via atm)
Release 2.0.4-alpha - UNRELEASED
INCOMPATIBLE CHANGES

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@ -24,6 +24,7 @@ import java.util.ArrayList;
import java.util.Hashtable;
import java.util.List;
import javax.naming.CommunicationException;
import javax.naming.Context;
import javax.naming.NamingEnumeration;
import javax.naming.NamingException;
@ -166,6 +167,8 @@ public class LdapGroupsMapping
private String groupMemberAttr;
private String groupNameAttr;
public static int RECONNECT_RETRY_COUNT = 3;
/**
* Returns list of groups for a user.
*
@ -178,34 +181,63 @@ public class LdapGroupsMapping
*/
@Override
public synchronized List<String> getGroups(String user) throws IOException {
List<String> groups = new ArrayList<String>();
List<String> emptyResults = new ArrayList<String>();
/*
* Normal garbage collection takes care of removing Context instances when they are no longer in use.
* Connections used by Context instances being garbage collected will be closed automatically.
* So in case connection is closed and gets CommunicationException, retry some times with new new DirContext/connection.
*/
try {
DirContext ctx = getDirContext();
// Search for the user. We'll only ever need to look at the first result
NamingEnumeration<SearchResult> results = ctx.search(baseDN,
userSearchFilter,
new Object[]{user},
SEARCH_CONTROLS);
if (results.hasMoreElements()) {
SearchResult result = results.nextElement();
String userDn = result.getNameInNamespace();
NamingEnumeration<SearchResult> groupResults =
ctx.search(baseDN,
"(&" + groupSearchFilter + "(" + groupMemberAttr + "={0}))",
new Object[]{userDn},
SEARCH_CONTROLS);
while (groupResults.hasMoreElements()) {
SearchResult groupResult = groupResults.nextElement();
Attribute groupName = groupResult.getAttributes().get(groupNameAttr);
groups.add(groupName.get().toString());
}
}
return doGetGroups(user);
} catch (CommunicationException e) {
LOG.warn("Connection is closed, will try to reconnect");
} catch (NamingException e) {
LOG.warn("Exception trying to get groups for user " + user, e);
return new ArrayList<String>();
return emptyResults;
}
int retryCount = 0;
while (retryCount ++ < RECONNECT_RETRY_COUNT) {
//reset ctx so that new DirContext can be created with new connection
this.ctx = null;
try {
return doGetGroups(user);
} catch (CommunicationException e) {
LOG.warn("Connection being closed, reconnecting failed, retryCount = " + retryCount);
} catch (NamingException e) {
LOG.warn("Exception trying to get groups for user " + user, e);
return emptyResults;
}
}
return emptyResults;
}
List<String> doGetGroups(String user) throws NamingException {
List<String> groups = new ArrayList<String>();
DirContext ctx = getDirContext();
// Search for the user. We'll only ever need to look at the first result
NamingEnumeration<SearchResult> results = ctx.search(baseDN,
userSearchFilter,
new Object[]{user},
SEARCH_CONTROLS);
if (results.hasMoreElements()) {
SearchResult result = results.nextElement();
String userDn = result.getNameInNamespace();
NamingEnumeration<SearchResult> groupResults =
ctx.search(baseDN,
"(&" + groupSearchFilter + "(" + groupMemberAttr + "={0}))",
new Object[]{userDn},
SEARCH_CONTROLS);
while (groupResults.hasMoreElements()) {
SearchResult groupResult = groupResults.nextElement();
Attribute groupName = groupResult.getAttributes().get(groupNameAttr);
groups.add(groupName.get().toString());
}
}
return groups;
@ -236,7 +268,7 @@ public class LdapGroupsMapping
return ctx;
}
/**
* Caches groups, no need to do that for this provider
*/

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@ -26,6 +26,7 @@ import java.io.Writer;
import java.util.Arrays;
import java.util.List;
import javax.naming.CommunicationException;
import javax.naming.NamingEnumeration;
import javax.naming.NamingException;
import javax.naming.directory.Attribute;
@ -46,21 +47,15 @@ public class TestLdapGroupsMapping {
private DirContext mockContext;
private LdapGroupsMapping mappingSpy = spy(new LdapGroupsMapping());
private NamingEnumeration mockUserNamingEnum = mock(NamingEnumeration.class);
private NamingEnumeration mockGroupNamingEnum = mock(NamingEnumeration.class);
private String[] testGroups = new String[] {"group1", "group2"};
@Before
public void setupMocks() throws NamingException {
mockContext = mock(DirContext.class);
doReturn(mockContext).when(mappingSpy).getDirContext();
NamingEnumeration mockUserNamingEnum = mock(NamingEnumeration.class);
NamingEnumeration mockGroupNamingEnum = mock(NamingEnumeration.class);
// The search functionality of the mock context is reused, so we will
// return the user NamingEnumeration first, and then the group
when(mockContext.search(anyString(), anyString(), any(Object[].class),
any(SearchControls.class)))
.thenReturn(mockUserNamingEnum, mockGroupNamingEnum);
SearchResult mockUserResult = mock(SearchResult.class);
// We only ever call hasMoreElements once for the user NamingEnum, so
// we can just have one return value
@ -76,23 +71,57 @@ public class TestLdapGroupsMapping {
// Define the attribute for the name of the first group
Attribute group1Attr = new BasicAttribute("cn");
group1Attr.add("group1");
group1Attr.add(testGroups[0]);
Attributes group1Attrs = new BasicAttributes();
group1Attrs.put(group1Attr);
// Define the attribute for the name of the second group
Attribute group2Attr = new BasicAttribute("cn");
group2Attr.add("group2");
group2Attr.add(testGroups[1]);
Attributes group2Attrs = new BasicAttributes();
group2Attrs.put(group2Attr);
// This search result gets reused, so return group1, then group2
when(mockGroupResult.getAttributes()).thenReturn(group1Attrs, group2Attrs);
}
@Test
public void testGetGroups() throws IOException, NamingException {
// The search functionality of the mock context is reused, so we will
// return the user NamingEnumeration first, and then the group
when(mockContext.search(anyString(), anyString(), any(Object[].class),
any(SearchControls.class)))
.thenReturn(mockUserNamingEnum, mockGroupNamingEnum);
doTestGetGroups(Arrays.asList(testGroups), 2);
}
@Test
public void testGetGroupsWithConnectionClosed() throws IOException, NamingException {
// The case mocks connection is closed/gc-ed, so the first search call throws CommunicationException,
// then after reconnected return the user NamingEnumeration first, and then the group
when(mockContext.search(anyString(), anyString(), any(Object[].class),
any(SearchControls.class)))
.thenThrow(new CommunicationException("Connection is closed"))
.thenReturn(mockUserNamingEnum, mockGroupNamingEnum);
// Although connection is down but after reconnected it still should retrieve the result groups
doTestGetGroups(Arrays.asList(testGroups), 1 + 2); // 1 is the first failure call
}
@Test
public void testGetGroupsWithLdapDown() throws IOException, NamingException {
// This mocks the case where Ldap server is down, and always throws CommunicationException
when(mockContext.search(anyString(), anyString(), any(Object[].class),
any(SearchControls.class)))
.thenThrow(new CommunicationException("Connection is closed"));
// Ldap server is down, no groups should be retrieved
doTestGetGroups(Arrays.asList(new String[] {}),
1 + LdapGroupsMapping.RECONNECT_RETRY_COUNT); // 1 is the first normal call
}
private void doTestGetGroups(List<String> expectedGroups, int searchTimes) throws IOException, NamingException {
Configuration conf = new Configuration();
// Set this, so we don't throw an exception
conf.set(LdapGroupsMapping.LDAP_URL_KEY, "ldap://test");
@ -102,10 +131,10 @@ public class TestLdapGroupsMapping {
// regardless of input
List<String> groups = mappingSpy.getGroups("some_user");
Assert.assertEquals(Arrays.asList("group1", "group2"), groups);
Assert.assertEquals(expectedGroups, groups);
// We should have searched for a user, and then two groups
verify(mockContext, times(2)).search(anyString(),
verify(mockContext, times(searchTimes)).search(anyString(),
anyString(),
any(Object[].class),
any(SearchControls.class));