Oracle Exadata

Oracle Exadata Architecture

Oracle exadata is an engineered system that combines database (compute) servers, storage servers, and high speed networking into an optimized platform for running Oracle Database workloads. Its architecture is designed to offload processing from database servers to intelligent storage, dramatically improving performance.

The Database servers (compute nodes) - include all the necessary hardware to run the Oracle Database for executing oracle scripts and queries to process large workloads. It typically uses Intel Xeon processors with large memory capacity. The database servers or compute nodes are connected via InfiniBand for high speed inter-node communication. 

Storage Servers (Exadata Storage Cells) - contain the actual data on high capacity disks (HDD) and flash storage (NVMs). These servers run the exadata storage server software which enables intelligent offloading. Each cell has its own CPUs, memory and flash cache.

InfiniBand Network - it is a ultra-low latency, high bandwidth network (upto 100 GB/s per port) which connects the database servers to the storage servers and enables RDMA (Remote Direct Memory Access) for efficient data transfer.

Ethernet Network - It is a client access network for application connections.

How it works  

• The client request arrive via ethernet to the database servers.
• The Oracle database RAC architecture distributes workload across the compute nodes for high availability.
• SQL processing begins on the database servers. eligible operations are offloaded.
• Smart Scan pushes filtering and projection down to the storage cells - only relevant data travels over InfiniBand.
• Storage indexes allow cells to skip regions that dont contain the required data based on the client request.
• Flash Cache accelerates frequently accessed data.
• Results are assembled on the database servers and returned to the clients.

Usage 

These exadata database machines are useful in large workload scenarios like datawarehousing, data analytics and off late in AI applications.

                                     

• Database Nodes – The Exadata Database Machine runs Oracle Database Real Application Cluster ( RAC ). The cluster and the database run on the servers known as database nodes or compute nodes (or simply “nodes”). A full rack has 8 nodes running on Oracle Linux or Oracle Solaris.
• Storage cells - The disks are not attached to the database compute nodes, as is normally the case with the direct attached storage, but rather to a different server known as the storage cell (or just “cell”; there are 14 of them in a full rack). The Oracle Exadata Server Software runs in these cells on top of the OS.
• Disks – each cell has 12 disks. Depending on the configuration, these disks are either 600GB high performance or 2TB high capacity (GB here means 1 billion bytes, not 1024MB). You have a choice in the disk type while making the purchase.
• Flash disks – each cell also has 384GB of flash disks. These disks can be presented to the compute nodes as storage (to be used by the database) or used a secondary cache for the database cluster (called smart cache).
• Infiniband circuitry – the cells and nodes are connected through infiniband for speed and low latency. There are 3 infiniband switches for redundancy and throughput. Note: there are no fiber switches since there is no fiber component.
• Ethernet switch – the outside world can communicate via infiniband, or by Ethernet. There is a set of Ethernet switches with ports open to the outside. The clients may connect to the nodes using Ethernet. DMAs and others connect to the nodes and cells using Ethernet as well. Backups are preferably via infiniband but they can be done through network as well.
• KVM switch – there is a keyboard, video, and mouse switch to get direct access to the nodes and cells physically. This is used initially while setting up and when the network to the system is not available.

References

Oracle Exadata

Oracle Exadata Architecture

God's Word for the day

Wisdon and Foolishness

The mind of a fool is like a broken jar;

  It can hold no knowledge.

When an intelligent person hears a wise saying he praises it and adds to it;

  When a fool hears it, he laughs at it and throws it behind his back.

A fool's chatter is like a burden on a journey,

  But delight is found in the speech of the intelligent.

The utterance of an intelligent person is sought in the assembly,

  And they ponder his words in their minds.

Sirach 21:15-17

Gospel teachings of Jesus

The parable of the sower explained

When anyone hears the word of the kingdom and does not understand it,

  the evil one comes and snatches away what is sown in the heart.

This is what was sown on the path.

  As for what was sown on rocky ground, this is the one who hears the word and immedialtely receives it with joy;

Yet such a person has no root, but endures only for a while,

  And when trouble or persecution arises on account of the word, that person immediately falls away.

As for what was sown among thorns, this is the one who hears the word,

  but the cares of the world and the lure of the wealth choke the word, and it yields nothing.

But as for what was sown on good soil, this is the one who hears the word and understands it,

  Who indeed bears fruit and yields, in one case a hundred fold, in another sixty, and in another thirty.

Mathew 13:18-23