FunZONE-4-Geeks

                      T his post is about creating a namespace in Aerospike. I could not find any concrete method to create a namespace like create database in MySQL and MongoDB. So I am suggesting a way to create a namespace in Aerospike Database. Step-1: Locate config file aerospike.conf and open it in your favorite editor and make sure you have permission to modify the file. In my system the path of file /etc/aerospike/aerospike.conf (Default in Ubuntu). Here the content of the file. # Aerospike database configuration file. service { user root group root paxos-single-replica-limit 1 # Number of nodes where the replica pidfile /var/run/aerospike/asd.pid service-threads 4 transaction-queues 4 transaction-threads-per-queue 4 proto-fd-max 15000 } logging { # Log file must be an absolute path. file /var/log/aerospike/aerospike.log { context any info } } net...

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If you are trying to connect Mongo DB Server and it insanely throwing following error. com.mongodb.MongoTimeoutException : Timed out after 1000 ms while waiting for a server that matches ReadPreferenceServerSelector{readPreference=primary}. Client view of cluster state is {type=UNKNOWN, servers=[{address=192.168.1.10:27010, type=UNKNOWN, state=CONNECTING, exception={ com.mongodb.MongoSecurityException: Exception authenticating MongoCredential {mechanism=null, userName='user123', source='admin', password=<hidden>, mechanismProperties={}}}, caused by {com.mongodb.MongoCommandException: Command failed with error 18 : 'Authentication failed.' on server 192.168.1.10:27010 . The full response is { "ok" : 0.0, "code" : 18, "errmsg" : "Authentication failed." }}}] If you start looking the error content First you encounter with Timeout Exception which may mislead you. It is basically an authentication error. I...

If you are just typing aql on terminal and following error throwing while your aerospike server has been started successfully. WARN AEROSPIKE_ERR_CLIENT Socket write error: 111 It may happen because you had connected some other server before, Now you are trying to connect to your localhost or different server. To remove the above error just type full command: aql -h 127.0.0.1 -p 3000                           ( put server ip in case of other server rather than localhost) instead of jus aql.

If you are trying to save a  whole simple java object into Aerospike database and your are getting the following annoying errors. com.aerospike.client.AerospikeException$Serialize: Error Code -1: java.io.NotSerializableException: com.sangnak-science. Person at com.aerospike.client.Value$BlobValue.estimateSize(Value.java:977) at com.aerospike.client.command.Command.estimateOperationSize(Command.java:767) at com.aerospike.client.command.Command.setWrite(Command.java:76) at com.aerospike.client.command.WriteCommand.writeBuffer(WriteCommand.java:56) at com.aerospike.client.command.SyncCommand.execute(SyncCommand.java:47) at com.aerospike.client.AerospikeClient.put(AerospikeClient.java:339) at com.yatra.Aerospike.main(Aerospike.java:57) Caused by: java.io.NotSerializableException: com.yatra.Person at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1184) at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:348) at com.aerospike.cli...

                      I n the following post we will see sample java code to perform simple operation (read, write and delete Records) from Aerospike Database System. The code are self explanatory, follow the comments in code for better understanding. You only need a jar for java client which you can download from aerospike official website. Main Class import java.util.ArrayList; import java.util.HashMap; import java.util.List; import java.util.Map; import com.aerospike.client.AerospikeClient; import com.aerospike.client.AerospikeException; import com.aerospike.client.Bin; import com.aerospike.client.Host; import com.aerospike.client.Key; import com.aerospike.client.Record; import com.aerospike.client.Value; import com.aerospike.client.policy.ClientPolicy; import com.aerospike.client.policy.WritePolicy; public class Aerospike { public static void main(String... args){ ...

Proxy Pattern The proxy pattern defines how to get object level access control by acting as a pass through entity or a placeholder object. There are three types in the proxy pattern. (1) Remote Proxy: Remote proxy represents an object locally which belongs to a different remote location. Real Life Example: ATM is remote proxy for the banks. (2) Virtual Proxy: When an object is complex or heavy, We can use a virtual proxy object as a skeleton representation for the original object. Real Life Example: Bank Cheques are the Virtual Proxy for the Currency Notes. (3) Protection Proxy: When we use a proxy to restrict the access of object it's called Protection proxy. Real Life Example: Proxy servers used in office and organizations to block the access of some websites and networks Java Code Example: Below is the java code example for the ATM Bank Implementation(Remote Proxy). The below code is not very good and secure for sophisticated banking system and...