Google Cloud Associate Engineer Certification

Recently I have prepared for GCP Associate Cloud Engineer exam and passed. Here are some of by observations –

• Exam questions are quite tricky not so much tough but basic knowledge of GCP should be there, some of the questions are really requires more attention as answers are really close to each other with some wording difference — take your time to read the question properly then respond.

• As Google FAQ said that some of the questions are not marked, they are just trial questions but actually you don’t know which one is trial so better to focus on the questions & make your attempt successful.

• There are also scenario-based questions which requires your knowledge to understand & respond.

• Topics mentioned in the exam details on Google site were covered. GCE, IAM, Google Groups, Copy Roles, GKE / App Engine, Cloud Storage (for Archiving – Coldline), Deployment Manager, KMS, Traffic Splitting VPC, gcloud commands, BigQuery & BigTable etc.

• I have an work experience on SAP BASIS & also working on cloud SAP projects, now this has been an added advantage for me to understand the cloud concepts however I had to learn a lot & also do hands on experience on Google Cloud.

• I have learned through Google official documentation for understanding the GCP concepts. It’s very comprehensive guide but obviously it’s requires hands on experience too because you don’t know when it goes deeper & wider.

• The self assessment tests given on Google official site is only for giving you a fair idea where you stand but doesn’t mean that you are ready to pass the exam. You have to go through each & every topic which mentioned in the official exam guide.

• Once you complete the test in the end you will get the provisional result indicating whether you passed or failed. Once you passed, within a day or so, you will get an official email from Google with Certification link.

• Like for any other exams, there is no break in this too. if you take break then it will minus from your exam time.

• Resources for learning –

o Google official documentation
o Udemy / Cloudera
o Braincert (for Practice exams)

Learning Resources

https://cloud.google.com/certification/cloud-engineer
• GCE: https://cloud.google.com/compute/docs/faq
• App Engine: https://cloud.google.com/appengine/kb/
• Google IAM: https://cloud.google.com/iam/docs/faq
• gcloud: https://cloud.google.com/sdk/gcloud/
• gcloud command reference: https://cloud.google.com/sdk/gcloud/reference/
• Storage FAQs: https://cloud.google.com/storage/docs/faq
• Cloud SQL FAQs: https://cloud.google.com/sql/faq
• gsutil command reference: https://cloud.google.com/storage/docs/gsutil (refer to gsutils Commands section)
• bq CLI reference: https://cloud.google.com/bigquery/docs/reference/bq-cli-reference
• Free Tier FAQs: https://cloud.google.com/free/docs/frequently-asked-questions
• Support: https://cloud.google.com/support/docs/
• Selecting storage options:https://cloud.google.com/images/storage-options/flowchart.svg
• GCP mapping to AWS & Azure:https://cloud.google.com/free/docs/map-aws-google-cloud-platform
https://cloud.google.com/free/docs/map-azure-google-cloud-platform
• Google Cost Calculator & Comparison: https://cloud.google.com/products/calculator/
https://cloud.google.com/pricing/#calculators
• 3rd Party Online Cost Comparison Websites:
https://calculator.unigma.com/
https://www.cloudorado.com/
• Practice Test:https://cloud.google.com/certification/practice-exam/cloud-engineer

Wish you the very best with your GCP certification. You can reach out to me for SAP BASIS or GCP short time consulting.

Can’t connect to X11 window server using ‘hostname:2’

If you are getting this below error in while opening SAPINST GUI in linux machine then run below command.

May 8, 2015 6:38:04 AM [Info]: GUI started.
May 8, 2015 6:38:04 AM [Info]: >> No protocol specified
May 8, 2015 6:38:04 AM [Info]: >> Closed input stream
May 8, 2015 6:38:04 AM [Error]: GUI terminated with return code 4
May 8, 2015 6:38:05 AM [Info]: >> Invocation target exception: Can’t connect to X11 window server using ‘hostname:2’ as the value of the DISPLAY variable; you may consider checking your DISPLAY environment variable.

xhost +

on base machine where we start vnc.

then ssh the host and start GUI.

SAP ECC 6.0 EHp 4.0 to EHp 5.0 Upgrade in Windows

Recently we have patched our SAP ECC system EHp 4.0 to EHp 5.0. EHP 5.0 requires Netweaver 7.0 EHP 2.0. As this is not a release upgrade but it still requires lot of efforts & time to complete, that’s why it’s call upgrade. We have calculated our STACK.xml file from SOLMAN 7.0 EHP 1 SP 23 (EHP 5.0 requires minimal level SP23). we stuck in lot of errors and it takes time to resolve it.

Before starting EHP upgrade always prepare a download directory and keep your all downloaded SAR & stack.xml  files in same directory. During upgrade sometimes EHPi got hangs & you feel it’s not working so please check abap/log or abap/tmp for any log or errors.

Below is the quick glance of errors which i faced during upgrade.

Go through this below SAP note before starting EHP upgrade.

1302772 General Installation Note

1.  Extraction Phase – Missing Notes – It will show you some missing notes. you have to import SAP notes in your ECC 6.0 EHP 4.0 system via SNOTE to continue. (some notes can only be applied in client 000 & can also requires functional people so make sure during note implementation you get confirmation from functional team)

2. Configuration Phase – SPAM Version Check –  To avoid this error update your SPAM to latest before starting upgrade.

3. Configuration Phase – Include Change Request – if you want to include any change request to be imported during upgrade to give details otherwise continue to skip this option.

4. Configuration Phase – Errors –  Download latest R3trans, tp & libdbsl(dbsoralib.dll) from Marketplace and extracts it to EHPI/abap/exenew & EHPI/abap/exe dir. This is the place where your new/extracted kernel resides, recheck that you are downloading the right R3trans & tp for your new kernel & also check R3trans -d( it should finish with 000) from your new kernel dir( i. e. abap/exe or abap/exenew)

5. Check Phase – Errors – Create Tablespace PSAPSR3702 with <given space>. This is the manual activity. you have to complete this activity via BRtools. You also get one file with name “ORATBSXT.LST”  in abap/log, in this file you will find how to create tablespace with recommended size.

6. Pre processing Phase –  Open repairs found – If your system is development system or any unreleased requests are there so release it or before proceed.

7. Pre processing Phase – MAIN_INIT/JOB_RSVBCHCK2 were Negative– Check log file and find the errors. this error occurs if you have any update request pending in SM13 or any outbound queue pending in SMQ1. Delete all the request from SM13 & SMQ1 and proceed. if it’s still giving error also run report RMCEX_SETUP_ENTRIES and delete the structural data or call transaction LBWG to delete the contents of the setup table  for all clients. Also check this SCN post http://scn.sap.com/thread/903136

8. Pre processing Phase – Lock development – This option will lock your development system for future development till upgrade.

9. Pre processing Phase – MAIN_SHADOW/START_SHDI_FIRST – failed to start shadow instance, check log file STARTFSI.log & DEVTRACE.log. usually this error occurs where there is short memory. in our case we check that if we down our main instance then shadow instance get up. both are not working simultaneously. we insert the parameter in shadow instance profile. (abap/heap_area_total = 2000000000) and also set the recommend page file size and restart the shadow instance. also check this SCN post – http://scn.sap.com/thread/1876639

10. Pre processing Phase – ACT_UPG – in our case ACT_UPG phase takes more then 12 hours to complete.

11.  Take full backup before downtime starts.

12. Downtime Phase – MAIN_SWITCH/KX_SWITCH_1 –  check log files, in our case EHPi fails to copy to 2 kernel files from exenew dir to /usr/sap/<SID>/…. we manually copy that 2 files and proceed.

13. Downtime Phase – MAIN_NEWBAS/STARTSAP_NBAS! –  check log files, in our case SAP error reading our instance profile from /usr/sap/<SID>/sys/profile. There was junk character in the profile but after removing that character EHPi again not able to read the profile so we copy the contents of our instance profile and create a new instance profile and then proceed.

14.  No more Errors in Downtime & Post Processing Phase.

We have completed our ECC 6.0 EHp 4.0 to EHp 5.0 successfully after these efforts. i was not able to note down the exact time for every phase.

Manual Post steps – in our case after logging to EHp 5.0 SAP system, we found that our Updates are deactivated, we activate the updates in SM13 & also create structure of financial. ( i forgot the exact thing as this is done by my colleague.)

SAP workprocesses can not connect to the database any more.

SAP Note 1519872 

Symptom

This note describes the configuration of an SAP installation with the SAP-pecific database user profile SAPUPROF.

Symptom:
SAP system does not start any more.
SAP workprocesses can not connect to the database any more.

SAP trace files contain errors similar to the following:
TRACE-INFO: 101:  [    dbsloci.,00000]  *** ERROR => CONNECT failed with sql error ‘28001’
TRACE-INFO: 102:  [     dev trc,00000]     set_ocica() -> SQL error code 28001
TRACE-INFO: 103:  [     dev trc,00000]    >oci_get_errmsg (con_hdl=0,rc=28001)
TRACE-INFO: 104:  [     dev trc,00000]     OCIErrorGet -> SQL error code: 28001
TRACE-INFO: 105:  [     dev trc,00000]     ORA-28001: the password has expired

Other symptoms:
You get ORA-28000 or ORA-28001 or ORA-28002 errors when you try to connect to the database (i.e. as database user SYSTEM).

Reason:

  • Oracle Database Release 11.2.0.X.
  • Database user profile SAPUPROF is not configured. Check this with the following query (for user SAPSR3):
    SQL> select profile from dba_users where username = ‘SAPSR3’;
  • With 11.2, passwords of database users must be changed every 180 days for security reasons.

For full solution, Please go through this note 1519872.

Free Screen Capture for Windows 7

After upgrading my laptop from Win XP to Win 7, I was unable to use ZAPGRAB as there is a compatibility issue with Win 7. For working in Win 7 you need to download the LICENSED version of ZAPGRAB. I have found many free screen captures programs on internet that can fulfill my requirements as ZAPGRAB do but didn’t find any good one.

After a lot of searching I have found “Greenshot” which is better than others & can also use in WIN 7. It’s an open source program.

Here is an download link of Greenshot official site http://getgreenshot.org/downloads/

Control file and its functions in Oracle.

Control file and its functions in Oracle

This article answers the following queries :
•         What is the control file in oracle?
•         What are the functions of control file in oracle?
•         What are the control file contents ?
•         Can database function properly without control file?
•         Can we edit control file
•         Who can modify control file?
•         At what time control file will be created?

What is control file in Oracle and what are its functions ?
Control file is a small binary file which is necessary for the database to start and operate successfully.

What are the functions of control file ?
Each control file is associated with only one database.  Oracle continuously updates control file during database use so this file must be available for writing whenever the database is in the open state.  Control file will be created at the same time of database creation.
Whenever a datafile or a redolog file is added to, dropped or renamed in the database, the control file is updated to reflect the physical structural change.
These changes are recorded in control file which facilitates:
>   Oracle to identify the files that are required or available in case database recovery is needed
>   Oracle to identify the datafiles and redolog files to open during database startup.

Can database function properly without control file?
No. Database cannot function properly if the control file is not available.

Can we edit control file? Who can modify control file?
Please note control file cannot be edited by database administrator or by any user. Control file information can only be modified by Oracle.

Contents of control files :
> Control file contains information such as
>   Database name
>   Timestamp of database creation
>   Tablespace information
>   The log history
>   Archive log information
>   Current log sequence number
>   Checkpoint information
>   Names and locations of associated datafiles and redolog files
>   Datafile copy information
>   Datafile offline ranges
>   Backup set and backup related information
>   Backup datafile and redolog information

SAPSR3 user locked.

Recently we find an issue that while starting SAP via SAP MMC, work process stop in Ended status. We found in developer trace that it’s a database connectivity issue. In some cases connectivity from SAP to Database does not happen due to SAPSR3 user locked.

Steps to find the issue in Windows Environment.

1. Go to CMD – R3trans -d (it ended with return code 0012)

2. Read the trans.log & search if there any user lock issue found.

if YES then go to below procedure to resolved.

1. Stop the SAP process in SAP MMC.

1. go to sqlplus via “CMD – sqlplus / as sysdba

2. execute statement to check which user(SAPSR3) is locked.

select username, account_status from dba_users;

find the list of dba users with their status. if SAPSR3 user is locked then execute this below statement to unlock.

alter user SAPSR3 account unlock;

again execute to check whether it’s successful or not.

select username, account_status from dba_users;

if successful log out from SQL & execute “R3trans -d“. it finish with RC=0000.

START SAP & it will start.

Changing data source ABAP to Database(default) in SAP Enterprise Portal.

Recently, I faced an issue in which I had to change the User Data Source of the portal to Database but I didn’t see the default option.

I got stuck after changing Portal — User Management — Identity Management — Data Source —- Database only to ABAP System.

After restarting the instance the value of Data Source shows only ABAP system & for somehow if you want to revert to Database only, it’s not possible. There is no any other options rather than ABAP System.

As per SAP note 718383.

dataSourceConfiguration_abap.xml

No change is possible.

This configuration supports all usages (especially SAP Exchange Infrastructure and SAP Enterprise Portal) by making ABAP users and ABAP roles available as users and groups in the UME, and supports the creation of new groups in the UME (which are then stored in the local database) as well.

The below SDN thread talks about same issue:

http://forums.sdn.sap.com/thread.jspa?messageID=10568533

SOLUTION:

You can change the database only(default) option by editing UME properties in Config Tool.

Steps to follow:

·         Config Tool — Global server configuration – services – com.sap.security.core.ume.service

·         ume.persistence.data_source_configuration (Make this value Restore to Default)

·         Restart the instance.

Now when you check again in Portal— User Management — Identity Management — Data Source

It will show the Database only(Default) value.

Enjoy!