Technology Questions

In a mapreduce job the master pings each worker periodically. In case a worker does not respond to that system then the system is marked as failed. Even completed tasks are rescheduled because the output was stored in a in a local disk of a worker which failed. Hence mapreduce is able to handle large-scale failures easily by simply restarting a task. The master node always saves itself at checkpoints and in case of any failure it simply restarts from that checkpoint.

Generating random passwords in PHP can be done in multiple ways depending on how much security the application demands:-

Md5 function can be passed one parameter as uniqid() function which in turn generates a random number. Passing the parameter as TRUE in uniqid() adds additional uniqueness.

<?php
   $passwd = md5(uniqid(rand(), true));
   Echo $passwd;
?>

- Multi-threading fetching in Amazon S3 is used to fetch the objects concurrently using the multiple threads and map the task so that fetching can be made simpler. 

- It is not a good practice to increase the threading for a particular object as every node on the server has some bandwidth constraints. 

- It provides user the ease with which they can upload the files and upload the threads in parallel. 

- It provides high speed of data transfer and easy maintenance of the sever as well.

- Use a COBOL II CALL statement to invoke a subprogram. This method is transparent to CICS, which sees only the one load module. 

- EXEC LINK is similar to a call; it invokes a separate CICS program and ends with a RETURN to the invoking program

- EXEC XCTL which transfers control to another CICS program and does not get control 

back. 

COBOL II allows for static calls which are more efficient than the LINK instruction which establishes a new run-unit. 

Optimized code tends to run faster and make more efficient use of the system’s resources. Optimized codes are also less susceptible to errors and take lesser space in memory and in file size.

.Net allows developers to write program logic in at least 25 languages. The classes written in one language can be used by other languages in .Net. This service of .Net is possible through CTS which ensure the rules related to data types that all language must follow. It provides set of types that are used by all .NET languages and ensures .NET language type compatibility.

User defined data-types in SQL is an extension to the base SQL server data-types by provision of a descriptive name.

We use them to format the database and segregate specific repetitions of rows and columns in the database.

MIME - Multi-purpose Internet Mail Extensions. 

MIME types represents a standard way of classifying file types over Internet. 

Web servers and browsers have a list of MIME types, which facilitates files transfer of the same type in the same way, irrespective of operating system they are working in.

A MIME type has two parts: a type and a subtype. They are separated by a slash (/). 

MIME type for Microsoft Word files is application and the subtype is msword, i.e. application/msword.