10.22.2017

How to install Oracle R Enterprise (ORE) on Exadata

Very recently, we have deployed ORE (R Distribution and R Enterprise) 3.1.1 packages on 4 node Exadata environment. This blog will discuss the prerequisites and procedure to deploy Oracle R Distribution v3.1.1.

Note: Ensure you have a latest system (root and /u01) backup before you deploy the packages on the db server.

What is R and Oracle Enterprise

R is third-party, open source software. Open source R is governed by GNU General Public License (GPL) and not by Oracle licensing. Oracle R Enterprise requires an installation of R on the server computer and on each client computer that interacts with the server.

Why Oracle R Distribution? 
  • Oracle R Distribution simplifies the installation of R for Oracle R Enterprise.
  • Oracle R Distribution is supported by Oracle for customers of Oracle Advanced Analytics, Oracle Linux, and Oracle Big Data Appliance.

What is needed for R Distribution deployment for Oracle Linux 6?

The Oracle R Distribution RPMs for Oracle Linux 6 are listed as follows:

http://public-yum.oracle.com/repo/OracleLinux/OL6/addons/x86_64/getPackage
        /R-3.1.1-2.el6.x86_64.rpm
http://public-yum.oracle.com/repo/OracleLinux/OL6/addons/x86_64/getPackage
        /R-core-3.1.1-2.el6.x86_64.rpm
http://public-yum.oracle.com/repo/OracleLinux/OL6/addons/x86_64/getPackage
        /R-devel-3.1.1-2.el6.x86_64.rpm
http://public-yum.oracle.com/repo/OracleLinux/OL6/addons/x86_64/getPackage
        /libRmath-3.1.1-2.el6.x86_64.rpm
http://public-yum.oracle.com/repo/OracleLinux/OL6/addons/x86_64/getPackage
       /libRmath-devel-3.1.1-2.el6.x86_64.rpm
http://public-yum.oracle.com/repo/OracleLinux/OL6/addons/x86_64/getPackage
       /libRmath-static-3.1.1-2.el6.x86_64.rpm
 
If the following dependent RPM is not automatically included, then download and install it explicitly:
texinfo-tex-4.13a-8.el6.x86_64.rpm

The picture below depicts the ORE client/server installation steps:


Description of Figure 1-2 follows

Oracle R Distribution on Oracle Linux Using RPMs

Oracle recommends that you use yum to install Oracle R Distribution, because yum automatically resolves RPM dependencies. However, if yum is not available, then you can install the RPMs directly and resolve the dependencies manually. Download the required rpms and its dependent rpms from below link:


http://yum.oracle.com/repo/OracleLinux/OL6/addons/x86_64/index.html

To know more about rpms and its dependent rpms, visit the following Oracle website:

https://docs.oracle.com/cd/E57012_01/doc.141/e57007/install_r.htm#BABECIBB

You can install the rpms in the following order:

yum localinstall libRmath-3.1.1-2.el6.x86_64.rpm
yum localinstall libRmath-devel-3.1.1-2.el6.x86_64.rpm
yum localinstall libRmath-static-3.1.1-2.el6.x86_64.rpm
yum localinstall R-core-3.1.1-2.el6.x86_64.rpm
yum localinstall R-devel-3.1.1-2.el6.x86_64.rpm
yum localinstall R-3.1.1-2.el6.x86_64.rpm

Once the rpms are installed, you can validate the installation , using the below procedure:

go to /usr/lib64/R directory on the database, as oracle user, type R:

You must see the output below:



type q() to exit from the R interface.

And repeat on the rest of the db nodes, if you are on RAC.

To install R distribution, use the procedure below:

rpm -e R-Rversion
rpm -e R-devel
rpm -e R-core
rpm -e libRmath-devel
rpm -e libRmath
 
 
 In the blog post, I will demonstrate how to configure Oracle R Enterprise.





10.19.2017

How to expand Exadata Database Storage capacity on demand



Exadata Storage expansion

Most of us knew the capabilities that Exadata Database Machine delivers. Its known fact that Exadata comes in different fixed rack size capacity: 1/8 rack (2 db nodes, 3 cells), quarter rack (2 db nodes, 3 cells), half rack (4 db nodes, 7 cells) and full rack (8 db nodes, 14 cells). When you want to expand the capacity, it must be in fixed size as well, like, 1/8 to quarter, quarter to half and half to full.

With Exadata X5 Elastic configuration, one can also have customized sizing by extending capacity of the rack by adding any number of DB servers or storage servers or combination of both, up to the maximum allowed capacity in the rack.

In this blog post, I will summarize and walk through a procedure about extending Exadata storage capacity, i.e, adding a new cell to an existing Exadata Database Machine.

Preparing to Extend Exadata Database Machine

·        Ensure HW placed in the rack, and all necessary network and cabling requirements are completed. (2 IPs from the management network is required for the new cell).
·         
·        Re-image or upgrade of image:
o   Extract the imageinfo from one of the existing cell server.
o   Login to the new cell through ILOM, connect to the console as root user and get the imageinfo
o   If the image version on the new cell doesn’t match with the existing image version, either you download the exact image version and re-image the new cell or upgrade the image on the existing servers.

Review "Reimaging Exadata Cell Node Guidance (Doc ID 2151671.1)" if you want to reimage the new cell.
  • Add the IP addresses acquired for the new cell to the /etc/oracle/cell/network-config/cellip.ora file on each DB node. To do this, perform the steps below from the first 1 db serer in the cluster:
    • cd /etc/oracle/cell/network-config
    • cp cellip.ora cellip.ora.orig
    • cp cellip.ora cellip.ora-bak
 
    • Add the new entries to /etc/oracle/cell/network-config/cellip.ora-bak.
    • /usr/local/bin/dcli -g database_nodes -l root -f cellip.ora-bak -d /etc/oracle/cell/network-config/cellip.ora

  • If ASR alerting was set up on the existing storage cells, configure cell ASR alerting for the cell being added.
    • List the cell attributes required for configuring cell ASR alerting. Run the following command from any existing storage grid cell:
o   CellCLI> list cell attributes snmpsubscriber
    • Apply the same SNMP values to the new cell by running the command below as the celladmin user, as shown in the below example:
o   CellCLI> alter cell snmpSubscriber=((host='10.20.14.21',port=162,community=public))
  • Configure cell alerting for the cell being added.
    • List the cell attributes required for configuring cell alerting. Run the following command from any existing storage grid cell:
o   CellCLI> list cell attributes
o    notificationMethod,notificationPolicy,smtpToAddr,smtpFrom,
o    smtpFromAddr,smtpServer,smtpUseSSL,smtpPort
    • Apply the same values to the new cell by running the command below as the celladmin user, as shown in the example below:
o   CellCLI> alter cell notificationmethod='mail,snmp',notificationpolicy='critical,warning,clear',smtptoaddr= 'dba@email.com',smtpfrom='Exadata',smtpfromaddr='dba@email.com',smtpserver='10.20.14.21',smtpusessl=FALSE,smtpport=25
  • Create cell disks on the cell being added.
    • Log in to the cell as celladmin and run the following command:
o   CellCLI> create celldisk all
    • Check that the flash log was created by default:
o   CellCLI> list flashlog
You should see the name of the flash log. It should look like cellnodename_FLASHLOG, and its status should be "normal".
If the flash log does not exist, create it using:
CellCLI> create flashlog all
    • Check the current flash cache mode and compare it to the flash cache mode on existing cells:
o   CellCLI> list cell attributes flashcachemode
To change the flash cache mode to match the flash cache mode of existing cells, do the following:
i. If the flash cache exists and the cell is in WriteBack flash cache mode, you must first flush the flash cache:
CellCLI> alter flashcache all flush
Wait for the command to return.
ii. Drop the flash cache:
CellCLI> "drop flashcache all"
iii. Change the flash cache mode:
CellCLI> "alter cell flashCacheMode=writeback_or_writethrough"
The value of the flashCacheMode attribute is either writeback or writethrough. The value must match the flash cache mode of the other storage cells in the cluster.
iv. Create the flash cache:
cellcli -e create flashcache all
  • Create grid disks on the cell being added.
    • Query the size and cachingpolicy of the existing grid disks from an existing cell.
o   CellCLI> list griddisk attributes name,asmDiskGroupName,cachingpolicy,size,offset
    • For each disk group found by the above command, create grid disks on the new cell that is being added to the cluster. Match the size and the cachingpolicy of the existing grid disks for the disk group reported by the command above. Grid disks should be created in the order of increasing offset to ensure similar layout and performance characteristics as the existing cells. For example, the "list griddisk" command could return something like this:
o   DATAC1          default         5.6953125T         32M
o   DBFS_DG         default         33.796875G         7.1192474365234375T
o   RECOC1          none            1.42388916015625T  5.6953582763671875T
When creating grid disks, begin with DATAC1, then RECOC1, and finally DBFS_DG using the following command:
CellCLI> create griddisk ALL HARDDISK PREFIX=DATAC1, size=5.6953125T, cachingpolicy='default', comment="Cluster cluster-clux6 DR diskgroup DATAC1"

CellCLI> create griddisk ALL HARDDISK PREFIX=RECOC1,size=1.42388916015625T, cachingpolicy='none', comment="Cluster cluster-clux6 DR diskgroup RECOC1"

CellCLI> create griddisk ALL HARDDISK PREFIX=DBFS_DG,size=33.796875G, cachingpolicy='default', comment="Cluster cluster-clux6 DR diskgroup DBFS_DG"
CAUTION: Be sure to specify the EXACT size shown along with the unit (either T or G).
  • Verify the newly created grid disks are visible from the Oracle RAC nodes. Log in to each Oracle RAC node and run the following command:
·        $GI_HOME/bin/kfod op=disks disks=all | grep cellName_being_added
This should list all the grid disks created in step 7 above.
  • Add the newly created grid disks to the respective existing ASM disk groups.
·        alter diskgroup disk_group_name add disk 'comma_separated_disk_names';
The command above kicks off an ASM rebalance at the default power level. Monitor the progress of the rebalance by querying gv$asm_operation:
SQL> select * from gv$asm_operation;
Once the rebalance completes, the addition of the cell to the Oracle RAC is complete.
  • Download and run the latest exachk to ensure that the resulting configuration implements the latest best practices for Oracle Exadata.
References:

http://docs.oracle.com/cd/E80920_01/DBMMR/extending-exadata.htm#DBMMR21158
Reimaging Exadata Cell Node Guidance (Doc ID 2151671.1)