London Stock Exchange Group Interview Questions and Answers

To resolve a production issue with no clue, follow a systematic troubleshooting approach.

• Start by gathering information about the issue, such as error messages, logs, and user reports.

• Analyze the available data to identify any patterns or commonalities that could help pinpoint the root cause.

• Review recent changes or deployments that might have introduced the issue.

• Consider reaching out to colleagues or experts for their insights and suggestions.

• If necessary, replicate the iss...read more

Quorum disk is a shared disk used in a Windows Server Failover Cluster to store cluster configuration data.

• Advantages: Provides a single point of reference for cluster configuration data, ensures consistency of data across all nodes, enables automatic failover of cluster resources.

• Disadvantages: Single point of failure, requires additional hardware, can be a bottleneck for cluster performance.

• Example: In a 3-node cluster, a quorum disk can be used to store the cluster configu...read more

Replication is the process of copying and distributing data from one database to another.

• Types of replication include snapshot replication, transactional replication, and merge replication.

• Snapshot replication copies the entire database at a specific point in time.

• Transactional replication copies only the changes made to the database since the last replication.

• Merge replication combines changes made to the database at different locations.

• Replication can be used for backup, re...read more

Failover types in cluster and always on

• In a cluster, failover can be automatic or manual

• In Always On, failover can be synchronous or asynchronous

• Automatic failover in a cluster requires a quorum of nodes to be available

• Synchronous failover in Always On ensures data consistency but can have higher latency

• Asynchronous failover in Always On has lower latency but may result in data loss

Checking file system involves verifying integrity and consistency of data stored on a disk. Boot processing is the sequence of steps that occur when a computer starts up. Daily troubleshooting issues involve identifying and resolving common problems that arise during regular use.

• To check file system, use built-in tools like chkdsk on Windows or fsck on Linux

• Boot processing involves BIOS/UEFI initialization, bootloader loading, kernel loading, and initialization of system serv...read more

Encryption can be created using various algorithms and keys to convert plain text into unreadable cipher text.

• Choose a strong encryption algorithm such as AES, RSA, or Blowfish

• Generate a unique key to encrypt and decrypt the data

• Implement the encryption algorithm in your code or use a library

• Ensure the encrypted data is securely stored and transmitted

• Consider using additional security measures such as hashing and salting