Oracle
Coherence In-Memory Data Grid is a Data Management System for application
objects that are shared across multiple Servers.
Data
Grid – is a system which contains multiple servers that actually work together
to manage information and operations related to them (computations) in a
Distributed Environment.
In
Memory Data Gird which stores information in memory which helps in achieving high
performance. This keeps copies of the information in sync with all other
servers ( in Cluster) to ensure data is available at all the time . Since the information
is saved with all other server ,the data will be available even when a server
is down.
Application
Objects are the components that the application use to store information .these
objects are shared across multiple servers and should survive server failures.
The
In-Memory Data Grid achieve low response times for data access by keeping the
information in memory which can be accessed by the application when it needed
in an application object form. The information is stored with all servers in
the cluster, this makes the application to access data from any of the server
in cluster.
Servers
can be added to the cluster for better performance, Since information is
synchronously replicated across multiple servers, so no Single Point of Failure
(SPOF) exists.
Each
server knows where the synchronous replicas of each piece of information are
located, and automatically re-routes information access and change operations
to those replicas.
Oracle
Coherence ensures that each operation executes in a Once-and-Only-Once manner,
so that operations that are being executed when a server fails do not
accidentally corrupt information during failover.
When
our applications need to process large amounts of data and also need good
response times , scalability , availability then Oracle coherence is a useful
component.
In
this article, we will see the basics of the Oracle Coherence configuration
1. Download
the Coherence Package from here
2. Once
we got the Coherence package, we can see 3 directories in there
Bin: contains
the Scripts For starting and Stopping of Coherence
Lib: contains
Libraries
Doc:
Documentation.
3. The
Coherence package contains 2 shell scripts which helps to identify whether
coherence works fine or not.
The
"cache server," is a simple
application that hosts and manages data on behalf of other applications in a
cluster.
The
"coherence shell," is a simple application that enables a developer
to access, process, and update cached data within a cluster. Information about
the Cluster can also be obtained from here. By executing these applications on
either a single host or several hosts, you can determine whether Coherence is
operating correctly locally or across a network.
Starting the Coherence Cache Server
The
cache-server can be started using the cache-server.sh script. Before starting
the server , we need to change a few settings into to work.
Export
COHERENCE_HOME with the path of the coherence home location and add the
Coherence bin location to the path.
export
COHERENCE_HOME=/soa/coherence
export PATH=$PATH://soa/coherence/bin
export PATH=$PATH://soa/coherence/bin
Once
the variable are added ,Now lets change the sh files
Open
the cache-server.sh and change COHERENCE_HOME,
COHERENCE_HOME=/soa/coherence/;
Now execute
the cache-server.sh
[root@vx111a
bin]# sh cache-server.sh
java
version "1.7.0_25"
Java(TM)
SE Runtime Environment (build 1.7.0_25-b15)
Java
HotSpot(TM) 64-Bit Server VM (build 23.25-b01, mixed mode)
2013-12-06
16:54:09.340/0.340 Oracle Coherence 3.7.1.0 <Info> (thread=main,
member=n/a): Loaded operational configuration from
"jar:file:/soa/coherence/lib/coherence.jar!/tangosol-coherence.xml"
2013-12-06
16:54:09.407/0.407 Oracle Coherence 3.7.1.0 <Info> (thread=main,
member=n/a): Loaded operational overrides from
"jar:file:/soa/coherence/lib/coherence.jar!/tangosol-coherence-override-dev.xml"
2013-12-06
16:54:09.408/0.408 Oracle Coherence 3.7.1.0 <D5> (thread=main,
member=n/a): Optional configuration override
"/tangosol-coherence-override.xml" is not specified
2013-12-06
16:54:09.412/0.412 Oracle Coherence 3.7.1.0 <D5> (thread=main,
member=n/a): Optional configuration override "/custom-mbeans.xml" is
not specified
Oracle
Coherence Version 3.7.1.0 Build 27797
Grid Edition: Development mode
Copyright
(c) 2000, 2011, Oracle and/or its affiliates. All rights reserved.
2013-12-06
16:54:09.678/0.678 Oracle Coherence GE 3.7.1.0 <Info> (thread=main,
member=n/a): Loaded cache configuration from
"jar:file:/soa/coherence/lib/coherence.jar!/coherence-cache-config.xml"
2013-12-06
16:54:10.163/1.163 Oracle Coherence GE 3.7.1.0 <Warning> (thread=main,
member=n/a): UnicastUdpSocket failed to set receive buffer size to 16 packets
(1023KB); actual size is 12%, 2 packets (127KB). Consult your OS documentation
regarding increasing the maximum socket buffer size. Proceeding with the actual
value may cause sub-optimal performance.
2013-12-06
16:54:10.163/1.163 Oracle Coherence GE 3.7.1.0 <Warning> (thread=main,
member=n/a): PreferredUnicastUdpSocket failed to set receive buffer size to
1444 packets (1.99MB); actual size is 6%, 90 packets (127KB). Consult your OS
documentation regarding increasing the maximum socket buffer size. Proceeding
with the actual value may cause sub-optimal performance.
2013-12-06
16:54:10.163/1.163 Oracle Coherence GE 3.7.1.0 <D4> (thread=main,
member=n/a): TCMP bound to /172.16.101.68:8088 using SystemSocketProvider
2013-12-06
16:54:10.164/1.164 Oracle Coherence GE 3.7.1.0 <Warning> (thread=main,
member=n/a): MulticastUdpSocket failed to set receive buffer size to 16 packets
(1023KB); actual size is 12%, 2 packets (127KB). Consult your OS documentation
regarding increasing the maximum socket buffer size. Proceeding with the actual
value may cause sub-optimal performance.
2013-12-06
16:54:13.429/4.429 Oracle Coherence GE 3.7.1.0 <Info> (thread=Cluster,
member=n/a): Created a new cluster "cluster:0xFCDB" with Member(Id=1,
Timestamp=2013-12-06 16:54:10.201, Address=172.16.101.68:8088, MachineId=55620,
Location=site:,process:4722, Role=CoherenceServer, Edition=Grid Edition,
Mode=Development, CpuCount=4, SocketCount=2) UID=0xAC10654400000142C7A68C59D9441F98
2013-12-06
16:54:13.434/4.434 Oracle Coherence GE 3.7.1.0 <Info> (thread=main,
member=n/a): Started cluster Name=cluster:0xFCDB
Group{Address=224.3.7.0,
Port=37000, TTL=4}
MasterMemberSet(
ThisMember=Member(Id=1, Timestamp=2013-12-06
16:54:10.201, Address=172.16.101.68:8088, MachineId=55620,
Location=site:,process:4722, Role=CoherenceServer)
OldestMember=Member(Id=1,
Timestamp=2013-12-06 16:54:10.201, Address=172.16.101.68:8088, MachineId=55620,
Location=site:,process:4722, Role=CoherenceServer)
ActualMemberSet=MemberSet(Size=1
Member(Id=1, Timestamp=2013-12-06
16:54:10.201, Address=172.16.101.68:8088, MachineId=55620,
Location=site:,process:4722, Role=CoherenceServer)
)
MemberId|ServiceVersion|ServiceJoined|MemberState
1|3.7.1|2013-12-06 16:54:13.429|JOINED
RecycleMillis=1200000
RecycleSet=MemberSet(Size=0
)
)
TcpRing{Connections=[]}
IpMonitor{AddressListSize=0}
2013-12-06
16:54:13.472/4.472 Oracle Coherence GE 3.7.1.0 <D5>
(thread=Invocation:Management, member=1): Service Management joined the cluster
with senior service member 1
2013-12-06
16:54:13.627/4.627 Oracle Coherence GE 3.7.1.0 <D5> (thread=DistributedCache,
member=1): Service DistributedCache joined the cluster with senior service
member 1
2013-12-06
16:54:13.701/4.701 Oracle Coherence GE 3.7.1.0 <D5>
(thread=ReplicatedCache, member=1): Service ReplicatedCache joined the cluster
with senior service member 1
2013-12-06
16:54:13.710/4.710 Oracle Coherence GE 3.7.1.0 <D5>
(thread=OptimisticCache, member=1): Service OptimisticCache joined the cluster
with senior service member 1
2013-12-06
16:54:13.716/4.716 Oracle Coherence GE 3.7.1.0 <D5> (thread=Invocation:InvocationService,
member=1): Service InvocationService joined the cluster with senior service
member 1
2013-12-06
16:54:13.719/4.719 Oracle Coherence GE 3.7.1.0 <Info> (thread=main,
member=1):
Services
(
ClusterService{Name=Cluster, State=(SERVICE_STARTED,
STATE_JOINED), Id=0, Version=3.7.1, OldestMemberId=1}
InvocationService{Name=Management,
State=(SERVICE_STARTED), Id=1, Version=3.1, OldestMemberId=1}
PartitionedCache{Name=DistributedCache,
State=(SERVICE_STARTED), LocalStorage=enabled, PartitionCount=257,
BackupCount=1, AssignedPartitions=257, BackupPartitions=0}
ReplicatedCache{Name=ReplicatedCache,
State=(SERVICE_STARTED), Id=3, Version=3.0, OldestMemberId=1}
Optimistic{Name=OptimisticCache,
State=(SERVICE_STARTED), Id=4, Version=3.0, OldestMemberId=1}
InvocationService{Name=InvocationService,
State=(SERVICE_STARTED), Id=5, Version=3.1, OldestMemberId=1}
)
Started DefaultCacheServer...
Once we
see the Started DefaultCacheServer, we are sure that the cache-server is
started.
Starting the Coherence
Once
the cache-server is started, now let start the Coherence shell.For this to
start we need to make a few Changes,
#
specify if the console will also act as a server
STORAGE_ENABLED=true
Make
sure that the STORAGE_ENABLED is set to true. If this is not set to true we see
messages like,
com.tangosol.net.RequestPolicyException:
No storage-enabled nodes exist for service DistributedCache
And we can’t put data into the cache.
Coherence
requires at least one storage enabled server in the cluster. The cache server
you started is not storage enabled. As an example, in .\bin directory of the
coherence install, there is a coherence.sh. By default, it is not storage
enabled. You can run cache-server.cmd to
start a storage enabled cache server.. Alternatively, you can edit coherence.cmd to change "set storage_enabled=false" to "set storage_enabled=true". Then you should be able to put data into the cache from the coherence.cmd command prompt.
start a storage enabled cache server.. Alternatively, you can edit coherence.cmd to change "set storage_enabled=false" to "set storage_enabled=true". Then you should be able to put data into the cache from the coherence.cmd command prompt.
Once
the Changes are done, start the shell using
[root@vx111a
bin]# sh coherence.sh
** Starting storage enabled console **
java
version "1.7.0_25"
Java(TM)
SE Runtime Environment (build 1.7.0_25-b15)
Java
HotSpot(TM) 64-Bit Server VM (build 23.25-b01, mixed mode)
2013-12-06
17:14:52.201/0.395 Oracle Coherence 3.7.1.0 <Info> (thread=main,
member=n/a): Loaded operational configuration from
"jar:file:/soa/coherence/lib/coherence.jar!/tangosol-coherence.xml"
2013-12-06
17:14:52.292/0.486 Oracle Coherence 3.7.1.0 <Info> (thread=main,
member=n/a): Loaded operational overrides from
"jar:file:/soa/coherence/lib/coherence.jar!/tangosol-coherence-override-dev.xml"
2013-12-06
17:14:52.292/0.486 Oracle Coherence 3.7.1.0 <D5> (thread=main,
member=n/a): Optional configuration override
"/tangosol-coherence-override.xml" is not specified
2013-12-06
17:14:52.298/0.492 Oracle Coherence 3.7.1.0 <D5> (thread=main,
member=n/a): Optional configuration override "/custom-mbeans.xml" is
not specified
Oracle
Coherence Version 3.7.1.0 Build 27797
Grid
Edition: Development mode
Copyright
(c) 2000, 2011, Oracle and/or its affiliates. All rights reserved.
2013-12-06
17:14:53.063/1.257 Oracle Coherence GE 3.7.1.0 <Warning> (thread=main,
member=n/a): UnicastUdpSocket failed to set receive buffer size to 16 packets
(1023KB); actual size is 12%, 2 packets (127KB). Consult your OS documentation
regarding increasing the maximum socket buffer size. Proceeding with the actual
value may cause sub-optimal performance.
2013-12-06
17:14:53.063/1.257 Oracle Coherence GE 3.7.1.0 <Warning> (thread=main,
member=n/a): PreferredUnicastUdpSocket failed to set receive buffer size to
1444 packets (1.99MB); actual size is 6%, 90 packets (127KB). Consult your OS
documentation regarding increasing the maximum socket buffer size. Proceeding
with the actual value may cause sub-optimal performance.
2013-12-06
17:14:53.063/1.257 Oracle Coherence GE 3.7.1.0 <D4> (thread=main,
member=n/a): TCMP bound to /172.16.101.68:8090 using SystemSocketProvider
2013-12-06
17:14:53.063/1.257 Oracle Coherence GE 3.7.1.0 <Warning> (thread=main,
member=n/a): MulticastUdpSocket failed to set receive buffer size to 16 packets
(1023KB); actual size is 12%, 2 packets (127KB). Consult your OS documentation
regarding increasing the maximum socket buffer size. Proceeding with the actual
value may cause sub-optimal performance.
2013-12-06
17:14:56.329/4.523 Oracle Coherence GE 3.7.1.0 <Info> (thread=Cluster,
member=n/a): Created a new cluster "cluster:0xFCDB" with Member(Id=1,
Timestamp=2013-12-06 17:14:53.1, Address=172.16.101.68:8090, MachineId=55620,
Location=site:,process:5124, Role=CoherenceConsole, Edition=Grid Edition,
Mode=Development, CpuCount=4, SocketCount=2)
UID=0xAC10654400000142C7B9836CD9441F9A
2013-12-06
17:14:56.333/4.527 Oracle Coherence GE 3.7.1.0 <Info> (thread=main,
member=n/a): Started cluster Name=cluster:0xFCDB
Group{Address=224.3.7.0,
Port=37000, TTL=4}
MasterMemberSet(
ThisMember=Member(Id=1, Timestamp=2013-12-06
17:14:53.1, Address=172.16.101.68:8090, MachineId=55620,
Location=site:,process:5124, Role=CoherenceConsole)
OldestMember=Member(Id=1,
Timestamp=2013-12-06 17:14:53.1, Address=172.16.101.68:8090, MachineId=55620,
Location=site:,process:5124, Role=CoherenceConsole)
ActualMemberSet=MemberSet(Size=1
Member(Id=1, Timestamp=2013-12-06
17:14:53.1, Address=172.16.101.68:8090, MachineId=55620,
Location=site:,process:5124, Role=CoherenceConsole)
)
MemberId|ServiceVersion|ServiceJoined|MemberState
1|3.7.1|2013-12-06 17:14:56.329|JOINED
RecycleMillis=1200000
RecycleSet=MemberSet(Size=0
)
)
TcpRing{Connections=[]}
IpMonitor{AddressListSize=0}
2013-12-06
17:14:56.367/4.561 Oracle Coherence GE 3.7.1.0 <D5>
(thread=Invocation:Management, member=1): Service Management joined the cluster
with senior service member 1
Map(?):
Once
you see the prompt mode , we can add cache and data to it like,
Map
(?): cache test
2013-12-06
17:15:00.968/9.162 Oracle Coherence GE 3.7.1.0 <Info> (thread=main,
member=1): Loaded cache configuration from
"jar:file:/soa/coherence/lib/coherence.jar!/coherence-cache-config.xml"
2013-12-06
17:15:01.181/9.375 Oracle Coherence GE 3.7.1.0 <D5>
(thread=DistributedCache, member=1): Service DistributedCache joined the
cluster with senior service member 1
<distributed-scheme>
<scheme-name>example-distributed</scheme-name>
<service-name>DistributedCache</service-name>
<backing-map-scheme>
<local-scheme>
<scheme-ref>example-binary-backing-map</scheme-ref>
</local-scheme>
</backing-map-scheme>
<autostart>true</autostart>
</distributed-scheme>
Map
(test): put foo bar
null
Map
(test): get foo
Bar
Or
Map
(?): maps animal
Map
(?): cache animal
2013-12-06
19:27:36.675/13.308 Oracle Coherence GE 3.7.1.0 <Info> (thread=main,
member=1): Loaded cache configuration from
"jar:file:/soa/coherence/lib/coherence.jar!/coherence-cache-config.xml"
2013-12-06
19:27:36.895/13.528 Oracle Coherence GE 3.7.1.0 <D5>
(thread=DistributedCache, member=1): Service DistributedCache joined the
cluster with senior service member 1
<distributed-scheme>
<scheme-name>example-distributed</scheme-name>
<service-name>DistributedCache</service-name>
<backing-map-scheme>
<local-scheme>
<scheme-ref>example-binary-backing-map</scheme-ref>
</local-scheme>
</backing-map-scheme>
<autostart>true</autostart>
</distributed-scheme>
Map
(animal): put 1 cat
null
Map
(animal): put 2 dog
null
Map
(animal): list
1 =
cat
2 =
dog
Map
(animal): get 1
cat
Map
(animal): get 2
dog
Map
(animal): put 3 bird
null
Map
(animal): list
1 =
cat
2 =
dog
3 =
bird
Coherence
Query Language
CohQL
is a new light-weight syntax (in the tradition of SQL) that is used to perform
cache operations on a Coherence cluster. The language can be used either
programmatically or from a command-line tool.
Coherence
package provides a shell script to invoke the COhQL mode.This can be invoked
using query.sh script. Before starting the script we need to make some changes.
Change,
#
specify if the console will also act as a server
STORAGE_ENABLED=true
COHERENCE_HOME=/soa/coherence/;
The JLINE_HOME environment
variable should be set to the location of the JLine JAR, which is used for
enhanced command-line editing capabilities, such as having the up and down
arrows move through the command history. Use the Default value provided.
[root@vx111a
bin]# sh query.sh
** Starting storage enabled console **
java
version "1.7.0_25"
Java(TM)
SE Runtime Environment (build 1.7.0_25-b15)
Java
HotSpot(TM) 64-Bit Server VM (build 23.25-b01, mixed mode)
Coherence
Command Line Tool
CohQL>
create cache "products"
2013-12-06
17:05:29.405/18.930 Oracle Coherence 3.7.1.0 <Info> (thread=main, member=n/a):
Loaded operational configuration from
"jar:file:/soa/coherence/lib/coherence.jar!/tangosol-coherence.xml"
2013-12-06
17:05:29.507/19.032 Oracle Coherence 3.7.1.0 <Info> (thread=main,
member=n/a): Loaded operational overrides from "jar:file:/soa/coherence/lib/coherence.jar!/tangosol-coherence-override-dev.xml"
2013-12-06
17:05:29.508/19.033 Oracle Coherence 3.7.1.0 <D5> (thread=main,
member=n/a): Optional configuration override
"/tangosol-coherence-override.xml" is not specified
2013-12-06
17:05:29.513/19.038 Oracle Coherence 3.7.1.0 <D5> (thread=main,
member=n/a): Optional configuration override "/custom-mbeans.xml" is
not specified
Oracle
Coherence Version 3.7.1.0 Build 27797
Grid Edition: Development mode
Copyright
(c) 2000, 2011, Oracle and/or its affiliates. All rights reserved.
2013-12-06
17:05:29.801/19.326 Oracle Coherence GE 3.7.1.0 <Info> (thread=main,
member=n/a): Loaded cache configuration from
"jar:file:/soa/coherence/lib/coherence.jar!/coherence-cache-config.xml"
2013-12-06
17:05:30.317/19.842 Oracle Coherence GE 3.7.1.0 <Warning> (thread=main,
member=n/a): UnicastUdpSocket failed to set receive buffer size to 16 packets
(1023KB); actual size is 12%, 2 packets (127KB). Consult your OS documentation
regarding increasing the maximum socket buffer size. Proceeding with the actual
value may cause sub-optimal performance.
2013-12-06
17:05:30.318/19.843 Oracle Coherence GE 3.7.1.0 <Warning> (thread=main,
member=n/a): PreferredUnicastUdpSocket failed to set receive buffer size to
1444 packets (1.99MB); actual size is 6%, 90 packets (127KB). Consult your OS
documentation regarding increasing the maximum socket buffer size. Proceeding
with the actual value may cause sub-optimal performance.
2013-12-06
17:05:30.318/19.843 Oracle Coherence GE 3.7.1.0 <D4> (thread=main,
member=n/a): TCMP bound to /172.16.101.68:8090 using SystemSocketProvider
2013-12-06
17:05:30.318/19.843 Oracle Coherence GE 3.7.1.0 <Warning> (thread=main,
member=n/a): MulticastUdpSocket failed to set receive buffer size to 16 packets
(1023KB); actual size is 12%, 2 packets (127KB). Consult your OS documentation
regarding increasing the maximum socket buffer size. Proceeding with the actual
value may cause sub-optimal performance.
2013-12-06
17:05:33.586/23.111 Oracle Coherence GE 3.7.1.0 <Info> (thread=Cluster,
member=n/a): Created a new cluster "Cluster" with Member(Id=1,
Timestamp=2013-12-06 17:05:30.355, Address=172.16.101.68:8090, MachineId=55620,
Location=site:,process:4984, Role=TangosolCoherenceQueryPlus, Edition=Grid
Edition, Mode=Development, CpuCount=4, SocketCount=2)
UID=0xAC10654400000142C7B0ED33D9441F9A
2013-12-06
17:05:33.591/23.116 Oracle Coherence GE 3.7.1.0 <Info> (thread=main,
member=n/a): Started cluster Name=Cluster
Group{Address=224.3.7.0,
Port=37000, TTL=4}
MasterMemberSet(
ThisMember=Member(Id=1, Timestamp=2013-12-06
17:05:30.355, Address=172.16.101.68:8090, MachineId=55620,
Location=site:,process:4984, Role=TangosolCoherenceQueryPlus)
OldestMember=Member(Id=1,
Timestamp=2013-12-06 17:05:30.355, Address=172.16.101.68:8090, MachineId=55620,
Location=site:,process:4984, Role=TangosolCoherenceQueryPlus)
ActualMemberSet=MemberSet(Size=1
Member(Id=1, Timestamp=2013-12-06
17:05:30.355, Address=172.16.101.68:8090, MachineId=55620,
Location=site:,process:4984, Role=TangosolCoherenceQueryPlus)
)
MemberId|ServiceVersion|ServiceJoined|MemberState
1|3.7.1|2013-12-06 17:05:33.586|JOINED
RecycleMillis=1200000
RecycleSet=MemberSet(Size=0
)
)
TcpRing{Connections=[]}
IpMonitor{AddressListSize=0}
2013-12-06
17:05:33.621/23.146 Oracle Coherence GE 3.7.1.0 <D5>
(thread=Invocation:Management, member=1): Service Management joined the cluster
with senior service member 1
2013-12-06
17:05:33.787/23.312 Oracle Coherence GE 3.7.1.0 <D5>
(thread=DistributedCache, member=1): Service DistributedCache joined the
cluster with senior service member 1
CohQL>
create cache "products"
CohQL>
insert into "products" key "telivision" value "TD-500"
CohQL>
select * from "products"
Results
TD-500
CohQL>
update "products" set value()="ID-501" where key() like
"telivision"
Results
telivision:
true
CohQL>
select * from "products"
Results
ID-501
CohQL>
CohQL>
select value(), key() from "products"
Results
"ID-501",
"telivision"
That’s it
about the basics of Oracle Coherence. In the next series we will see how to
configure Oracle Coherence with Oracle Weblogic.
More to Come,
Happy Coding.
