| Oracle® Coherence Release Notes for Oracle Coherence Release 3.5.2 Part Number E15884-01 |
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| Oracle® Coherence Release Notes for Oracle Coherence Release 3.5.2 Part Number E15884-01 |
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View PDF |
This chapter describes changes, enhancements, and corrections made to the Oracle Coherence documentation library for the 3.5.2 release. The library can be found at the following URL:
http://download.oracle.com/docs/cd/E14526_01/index.htm
This chapter contains the following sections:
A change has been made to the Defining a Data Grid chapter of Getting Started with Oracle Coherence. The reference to Ruby as a supported object-oriented language for an application object has been removed.
Table 2-1 Changes to Defining a Data Grid
A addition has been made to the Large Cluster Configuration section of the Production Checklist appendix in the Developer's Guide for Oracle Coherence.
Table 2-2 Changes to Production Checklist Description
A change has been made to the question What are the supported and suggested server operating systems for deploying Coherence on? in the Operating Systems section of the Production Checklist appendix.
Table 2-3 Changes to Linux Support
In the Advanced: Listening to Queries section of Deliver Events for Changes as they Occur, in Getting Started with Oracle Coherence, the name of the trades class (for example, trades.addMapListener(listener, new MapEventFilter(filter), true)) has been changed to mapTrades (for example, mapTrades.addMapListener(listener, new MapEventFilter(filter), true)).
A change has been made to the DOCTYPE declaration for the Coherence Operational Configuration deployment descriptor in the Document Format section of the Operational Configuration Elements appendix of the Developer's Guide for Oracle Coherence. The DOCTYPE declaration has been changed from this:
<!DOCTYPE coherence PUBLIC "-//Oracle, Inc.//DTD Oracle Coherence 3.5//EN" "http://www.tangosol.com/dtd/coherence_3_3.dtd">
to this:
<!DOCTYPE coherence SYSTEM "coherence.dtd">
Updates have been made to the following links in the description of the bdb-store-manager element in Cache Configuration Elements appendix in the Developer's Guide for Oracle Coherence.
The new link to the Berkeley Database JE is: http://www.oracle.com/technology/documentation/berkeley-db/je/index.html
The new link to the Berkeley DB Configuration is: http://www.oracle.com/technology/documentation/berkeley-db/je/GettingStartedGuide/administration.html#propertyfile
Changes have been made to the descriptions of the following member-identity sub-elements in the Operational Configuration Elements appendix in the Developer's Guide for Oracle Coherence:
Table 2-4 Changes to member-identity Element Description
Changes have been made to the descriptions of the partitioned and partition-count sub-elements of the distributed-scheme element in the Cache Configuration Elements appendix in the Developer's Guide for Oracle Coherence.
The following changes were made to the note in the partitioned description:
When using an off-heap backing map it is important that the corresponding backup-storage be configured for off-heap (potentially using the same scheme as the backing-map). Here off-heap refers to any storage where some or all entries are stored outside of the JVMs garbage collected heap space. Examples include overflow-scheme, and external-scheme. See the Partitioned cache with overflow sample in the Sample Cache Configurations appendix for an example configuration.
The following is the new description of the partitioned-count sub-element:
<partition-count> (Optional)—Specifies the number of partitions that a partitioned (distributed) cache will be "chopped up" into. Each member running the partitioned cache service that has the local-storage option set to true will manage a "fair" (balanced) number of partitions.
Legal values are positive integers. The number of partitions should be a prime number and sufficiently large such that a given partition is expected to be no larger than 50MB. A list of first 1,000 primes can be found at this URL: http://www.utm.edu/research/primes/lists/small/1000.txt
Good default values for example service storage sizes are provided in Table 2-5:
A change has been made to the description of the tcp-acceptor element in the Cache Configuration Elements appendix in the Developer's Guide for Oracle Coherence.
The <tcp-acceptor> element can use either an <address-provider> or a <local-address> element.The address-provider sub-element specifies the configuration for the com.tangosol.util.AddressProvider address factory that will supply the local address (IP or DNS name) and port that the TCP/IP ServerSocket opened by the connection acceptor will listen on.
The following error messages have been added to the Log Message Glossary appendix in the Developer's Guide for Oracle Coherence.
Failover Related Messages
validatePolls: This service timed-out due to unanswered handshake request. Manual intervention is required to stop the members that have not responded to this Poll
| Parameters | none |
| Severity | 1-Error |
| Cause | When a node joins a clustered service, it performs a handshake with each clustered node running the service. A missing handshake response prevents this node from joining the service. Most commonly, it is caused by an unresponsive (for example, "deadlocked") service thread. |
| Action | Corrective action may require locating and shutting down the JVM running the unresponsive service. See My Oracle Support Note 845363.1: https://metalink.oracle.com/CSP/main/article?cmd=show&type=NOT&id=845363.1 for more details. |
Cache Related Messages
Error while starting cluster: com.tangosol.net.RequestTimeoutException: Timeout during service start: ServiceInfo(%s)
| Parameters | %s - information on the service that could not be started |
| Severity | 1-Error |
| Cause | When joining a service, every service in the cluster must respond to the join request. If one or more nodes have a service that does not respond within the timeout period, the join times out. |
| Action | See My Oracle Support Note 845363.1: https://metalink.oracle.com/CSP/main/article?cmd=show&type=NOT&id=845363.1 for more details. |
Failed to restart services: com.tangosol.net.RequestTimeoutException: Timeout during service start: ServiceInfo(%s)
| Parameters | %s - information on the service that could not be started |
| Severity | 1-Error |
| Cause | When joining a service, every service in the cluster must respond to the join request. If one or more nodes have a service that does not respond within the timeout period, the join times out. |
| Action | See My Oracle Support Note 845363.1: https://metalink.oracle.com/CSP/main/article?cmd=show&type=NOT&id=845363.1 for more details. |
In Coherence, extractors and updaters are used to extract and update values of objects that are stored in the cache. PofExtractors and PofUpdaters take advantage of POF's indexed state to extract or update an object without requiring full serialization or deserialization routines.
PofExtractors and PofUpdaters adds flexibility in working with non-primitive types in Coherence. For most cases, where you're working with extend clients, it is no longer required to have corresponding Java classes in the grid. Because PofExtractors and PofUpdaters can navigate the binary, the entire key/value does not have to be deserialized into Object form. This implies that indexing can be achieved by simply using a PofExtractor to pull a value to index on. There are, however, circumstances where you must provide a corresponding Java class:
Key Association—When using key association, Coherence always deserializes keys to determine whether they implement KeyAssociation.
Cache Stores—When using a cache store, Coherence passes the deserialized version of the key and value to the cache store to write to the back end.
Due to the fact that the Portable Object Format is indexed, it is possible to quickly traverse the binary to a specific element for extraction or updating. It is the responsibility of the com.tangosol.io.pof.reflect.PofNavigator interface to traverse a POF value object and return the desired POF value object. Out of the box, Coherence provides a com.tangosol.io.pof.reflect.SimplePofPath class that can navigate a POF value based on integer indexes. In the simplest form, all you must do is to provide the index of the attribute to extract or update.
The Contact class illustrated in Example 2-1 defines a constant for each data member that is being written to and from the POF stream. This is an excellent practice to follow as it will simplify both writing your serialization routines as well as making it easier to work with PofExtractors and PofUpdaters. By labeling each index, it becomes much easier to think about what you are working with. As mentioned earlier, in the simplest case, you could pull the work address out of the contact by using the WORK_ADDRESS index. The SimplePofPath also allows using an Array of ints to traverse the PofValues. For example, if you wanted the zip code of the work address you would use [WORK_ADDRESS, ZIP]. The following sections will go through the example in greater detail.
Example 2-1 A Java Class with Indexed Data Members
public class Contact
implements PortableObject
{
...
// ----- PortableObject interface ---------------------------------------
/**
* {@inheritDoc}
*/
public void readExternal(PofReader reader)
throws IOException
{
m_sFirstName = reader.readString(FIRSTNAME);
m_sLastName = reader.readString(LASTNAME);
m_addrHome = (Address) reader.readObject(HOME_ADDRESS);
m_addrWork = (Address) reader.readObject(WORK_ADDRESS);
m_mapPhoneNumber = reader.readMap(PHONE_NUMBERS, null);
}
/**
* {@inheritDoc}
*/
public void writeExternal(PofWriter writer)
throws IOException
{
writer.writeString(FIRSTNAME, m_sFirstName);
writer.writeString(LASTNAME, m_sLastName);
writer.writeObject(HOME_ADDRESS, m_addrHome);
writer.writeObject(WORK_ADDRESS, m_addrWork);
writer.writeMap(PHONE_NUMBERS, m_mapPhoneNumber);
}
....
// ----- constants -------------------------------------------------------
/**
* The POF index for the FirstName property
*/
public static final int FIRSTNAME = 0;
/**
* The POF index for the LastName property
*/
public static final int LASTNAME = 1;
/**
* The POF index for the HomeAddress property
*/
public static final int HOME_ADDRESS = 2;
/**
* The POF index for the WorkAddress property
*/
public static final int WORK_ADDRESS = 3;
/**
* The POF index for the PhoneNumbers property
*/
public static final int PHONE_NUMBERS = 4;
...
}
Note:
In Release 3.5.2, a newClass parameter has been added to the PofExtractor constructors.Extractors are typically used when querying the cache. Using a PofExtractor should greatly improve the performance of your queries. If you were to use the class illustrated in Example 2-1, and wanted to query the cache for all Contacts with the last names Jones, the query would look something like this:
ValueExtractor veName = new PofExtractor(String.class, Contact.LASTNAME); Filter filter = new EqualsFilter(veName, "Jones"); // find all entries that have a last name of Jones Set setEntries = cache.entrySet(filter);
In this use case, the PofExtractor has a convenience constructor that will use a SimplePofPath to retrieve a singular index, in this case, the Contact.LASTNAME index. Now, if you wanted to find all Contacts with the area code 01803, the query would look like this:
ValueExtractor veZip = new PofExtractor(
String.class, new SimplePofPath(new int[] {Contact.WORK_ADDRESS, Address.ZIP}));
Filter filter = new EqualsFilter(veZip, "01803");
// find all entries that have a work address in the 01803 zip code
Set setEntries = cache.entrySet(filter);
Notice that in the previous examples, the PofExtractor constructor has a first argument (added in 3.5.2) with the class of the extracted value or null. The reason for passing type information is that POF uses a compact form in the serialized value when possible. For example, some numeric values are represented as special POF intrinsic types in which the type implies the value. As a result, POF requires the receiver of a value to have implicit knowledge of the type. PofExtractor uses the class supplied in the constructor as the source of the type information. If the class is null, PofExtractor will infer the type from the serialized state, but the extracted type may differ from the expected type. Strings, in fact, can be correctly inferred from the POF stream, so null is sufficient in the previous examples. In general, however, null should not be used.
PofUpdaters work in the same way as PofExtractors except that they update the value of an object rather than extract it. So, to change all entries with the last name of Jones to Smith, use the UpdaterProcessor like this:
ValueExtractor veName = new PofExtractor(String.class, Contact.LASTNAME); Filter filter = new EqualsFilter(veName, "Jones"); ValueUpdater updater = new PofUpdator(Contact.LASTNAME); // find all Contacts with the last name Jones and change them to have the last name "Smith" cache.invokeAll(filter, new UpdaterProcessor(updater, "Smith"));
Note:
While these examples operate on String based values, this functionality will work on any POF encoded value.
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