One of the big use cases for Oracle Cloud Infrastructure (OCI) formerly known as Baremetal Cloud is noSQL and newSQL. Oracle says what big advantage on storage layer would be PCIe based NVMe SSD with super low latency. And elimination of virtualization layer would let it shine at full. While MemSQL row store is in-memory, […]
Steps: Start Spark Thrift Server on Datastax Cluster Enable Qlik Server’s Security Group on AWS to access port 10000 (basically from qlik, need to connect to thrift server port 10000) Install Simba ODBC Driver for Spark on the Qilk Windows EC2 InstanceCreate System DSN as follows: Spark Server Type: SparkThriftServer Host: internal-spark-thriftserver-prod-lb-861234576.ap-southeast-1.elb.amazonaws.com (DNS name of […]
DSE 5.0.6, Spark 1.6.2 Example 1 From cqlsh, below query works Below query does a Full Table Scan(FTS) Below query does not do FTS, because leading partition key column is txn_status Below query does not return result at all if txn_date is not cast Example 2 Example 3 Example 4 Example 5 CATEGORIES
One of the big use cases for Oracle Cloud Infrastructure (OCI) formerly known as Baremetal Cloud is noSQL and newSQL. Oracle states what big advantage on storage layer would be PCIe based NVMe SSD with super low latency. And elimination of virtualization layer would let it shine at full. While MemSQL row store is in-memory, […]
DSE 5.0.7, Spark 1.6.3 Accessing Spark Accessing spark from outside the spark cluster Spark SQL Pyspark Scala Spark Job Spark Thrift / Beeline note Difference between thrift query and spark-sql query, is that thrift server uses a shared SparkSQL context whereas Spark SQL does not. Accessing Cassandra Materialized Views from Spark users_by_email_mview is a materialized […]
Configuration: DSE 5.0.6 (See Datastax Cassandra on AWS for Installation Details) so when you start dse spark or dse spark-sql, in spark UI, you can see 3 out of 4 cores allocated Verification: Finding the spark master Spark Web UI: http://<node1>:7080Now in http://:4040/stages/, we can see 1 Fair Scheduler Pool, with schedule mode as FAIRFrom AWS […]
Here is a quick example how to install Oracle Braremetal cloud cli on MacOS or Linux.Please note what oracle just renamed Braremetal cloud to Oracle Cloud Infrastructure (OCI) First thing first – python. I recommend to start with Python 3.6 or later. Oracle says python 2 is also supported, but when I tried bmcs installed […]
Setting up AWS EC2 Instance Type: m4.xlarge, 4 node cluster, 2 in each AZStorage: Two EBS volumes, data volume 400GB, 150GB log volume, root volume 150GB (General Purpose SSD)OS:Amazon Linux AMI 2016.09.0 (HVM), SSD Volume Type – ami-b953f2daThe Amazon Linux AMI is an EBS-backed, AWS-supported image. The default image includes AWS command line tools, Python, Ruby, Perl, […]
If you have situation when partition elimination/pruning does not work, here are couple effective tricks to fix it. 1. If query derives partition key from sub-query, for example (query where sale_date is a partition key): Replace sub-query with DETERMINISTIC function: In most cases it should not be differences between sub-query and function. But there are […]
Choice of Tool New Relic http://newrelic.com/plugins/3legs/113Monitor Cassandra statistics using the 3legs plugin. Metrics include Read and Write latency (global and per host), Cache statistics, Pending compactions, flushes and more. Datastax – OpsCenter http://www.datastax.com/documentation/opscenter/4.1/pdf/opscuserguide41.pdfDataStax OpsCenter is a visual management and monitoring solution for Apache Cassandra and DataStax Enterprise.The DataStax agents are installed on the Real-time (Cassandra), […]
There are several problem common problems with Juniper SSL VPN on support of Linux clients: 1.Most 64-bit platforms are not supported.2.Junos Pulse SSL VPN does not support Linux at all. Best way to cover problem “1” is:http://ubuntuforums.org/showthread.php?p=11189826#post11189826There is also well known mad-scientist way but its more complex. Problem “2” is a bit more involved. In […]
If you see “ORA-01555: snapshot too old” from Select what is been run on Physical standby, but same select runs on primary just fine, and all relevant init.ora parameters and undo tablespace are exactly identical between primary and standby,- its odd. But its easy to explain. First check if DB is below 11.2.0.3 DB it […]
Its Unix 101 statement, but I have heard it wrong so many time, so decided to put a blog for it. If in OLTP environment, per ‘top’ %wa (IOWAIT) is major contributor for CPU busy, adding CPU would not help. There is no need for more CPU. Period. ************** %wa IS PERCENTAGE WHAT COUNT TO […]
High Index Clustering factor is popular problem in SQL world.The most known solution for it – rebuild table ordering by columns what are in the index.But in real world, with table size growing exponentially its not always practical or possible to do it. Here is one way to avoid index clustering problem by SQL optimization.. […]