Apache Airflow Rest API

Hello everyone,

Today I’ll talk about Apache Airflow usage, a REST API.

I frequently have customers asking about Apache Airflow’s integration with their own applications. “How can I execute a job from my application?” or “how can I get my job status in my dashboard?” are good examples of the questions I receive the most.

I’ll use the following question from a customer to show this great feature in Apache Airflow:

“ I would like to call one specific job orchestrated in Apache Airflow environment  in my application, is it possible?”

Quick answer: “Yes, all that you need to do is to call the Airflow DAG using REST API …..“

Details:

The simplest way to show how to achieve this is by using curl to call my Apache Airflow environment. I had one DAG to execute this from a bash operator. Quick example:

curl -X POST \

  http://localhost:8080/api/experimental/dags/my_bash_oeprator/dag_runs \

  -H ‘Cache-Control: no-cache’ \

  -H ‘Content-Type: application/json’ \

  -d ‘{“conf”:”{\”key\”:\”value\”}”}’

The curl execution returns the execution date id, with this ID you can use to get an execution status. Like this:

curl -X GET  http://localhost:8080/api/experimental/dags/my_bash_oeprator/dag_runs/2020-04-05T00:26:35

{“state”:”running”}

This command can also return other status {“state”:”failed”} or {“state”:”success”}.

I hope you enjoy it!

GUORS: I Encontro de Usuários Oracle do RS 2020 (Online)

Olá pessoal,

Teremos evento dos GUORS no primeiro semestre, como de costume!

Porém desta vez será online!

Será no dia 21/5 (quinta-feira) as 20:00.
Onde? No conforto de sua casa!

Contaremos com a presença ilustre do Oracle ACE Marcus Vinicius falando sobre OCI for Oracle DBA’s: Introduction and Key Concepts.

Nessa sessão o nosso convidado falará sobre o OCI (Oracle Cloud Infrastructure), conceitos-chave e os desafios de um DBA Oracle na conversão de sua carreira para arquiteto Cloud a partir da perspectiva de quem vive esta experiência cotidianamente.

O Marcus Vinicius é DBA Oracle Sênior, Oracle ACE e possui diversas certificações em Bancos de Dados Oracle. Possui mais de 15 anos de experiência na área. Foi professor de pós-graduação no curso “MBA em Administração de Banco de Dados Oracle” no Veris IBTA, unidades de São Paulo e Campinas. Foi também DBA Oracle e Gerente de Operações na Discover Technology e Consultor Oracle Sênior na Oracle (ACS). Atualmente é Consultor Oracle Sênior na Accenture Enkitec Group. Também é conselheiro técnico do GUOB. Mantém um blog sobre Oracle há mais de 10 anos – https://www.viniciusdba.com.br/blog (não deixa de conhecer o Blog do Vini também!).

Não vai perder essa né?

Faça a sua inscrição AQUI!

Cloud computing

ALTERNATE Archive log destination configuration that can help you – at least it helped me =)

Hi all,

I was working on a database that was waiting on a backup policy to be configured on the Netbackup side, so basically it had no backups. No news here right =)

The dev team did not wait for much to hammer down the database which caused the archive log generation spiked high.

They were planning to work all weekend long and I needed to make sure that the database was available.

I had a spare diskgroup that I could use when the FRA got full but I did not wanted to monitor the space usage along the weekend to change the archive log destination, also did not want set it up ahead of it causing to double the archive log being sent to both locations wasting space.

So, one active location at a particular time and if /when the 1st location filled up, it would switch to the secondary location.

The configuration that helped me with was the ALTERNATE parameter in the log_archive_dest_n.

The parameter “Specifies an alternate archiving destination to be used when the original destination fails.”

If you want you can read the all details of the parameter here 

Most of the configurations using this parameter are related to the Dataguard standby configurations but it works on this scenario as well.

This is how I used it:
*I used the noreopen configuration as I knew that the space issue would not be resolved during the weekend

alter system set log_archive_dest_1='location=use_db_recovery_file_dest noreopen alternate=log_archive_dest_2' scope=both sid'*';
alter system set log_archive_dest_2='+NEW_FLASH´ sid='*';
alter system set log_archive_dest_state_2= 'ALTERNATE' scope=both sid='*';

On the database, you can see the status of the archive destinations:

select dest_id, dest_name, status from v$archive_dest_status where status <> 'INACTIVE';

DEST_ID DEST_NAME STATUS
---------- -------------------- ---------
1 LOG_ARCHIVE_DEST_1 VALID
2 LOG_ARCHIVE_DEST_2 UNKNOWN

I saw this error in the alert when the space on the 1st destination exhausted (also some hiccups on the database´s services):

ORA-17502: ksfdcre:4 Failed to create file +FLASH
ORA-15041: diskgroup "+FLASH" space exhausted
ORA-16038: log 8 sequence# 1059 cannot be archived
ORA-19504: failed to create file ""

Checking the log_archive_dest parameter status, the 1st one got disabled and only the 2nd was is valid, the hickups were baralley noticed andthe database kept working all the time.

select dest_id, dest_name, status from v$archive_dest_status where status <> 'INACTIVE';

DEST_ID DEST_NAME STATUS
---------- -------------------- ---------
1 LOG_ARCHIVE_DEST_1 DISABLED
2 LOG_ARCHIVE_DEST_2 VALID

When the space issue was resolved, all I needed to do was to enable the 1st location and set the 2nd one again to alternate.

select dest_id, dest_name, status from v$archive_dest_status where status <> 'INACTIVE';

DEST_ID DEST_NAME STATUS
---------- -------------------- ---------
1 LOG_ARCHIVE_DEST_1 VALID
2 LOG_ARCHIVE_DEST_2 UNKNOWN

Thanks and hope it helps

Elisson Almeida

Virtual Conference: Systematic Oracle SQL Optimization in 2020 (Review)

Hi all,

I’m here for a review and for a tip: Please don’t miss it in case those guys decide to do it again!

It was a really great conference, with a lot of really valuable sessions with real content.

I’ll just share the agenda so you can imagine by yourself. There is more in https://tanelpoder.com/conference/.

Day 1 Speaker Topic
11:00-11:15 Tanel Welcome & Introduction
11:15-12:30 Cary A Richer Understanding of Software Performance
12:30-13:00 Slack Break/Q&A/Chat
13:00-14:30 Jonathan Trouble-shooting with Execution Plans
14:30-15:00 All Speakers Panel: What Has Changed in 10 Years and What Has Not

 

Day 2 Speaker Topic
11:00-11:15 Kerry How to Stay Relevant
11:15-12:30 Tanel Scripts and Tools for Optimizing SQL Execution and Indexing
12:30-13:00 Slack Break/Q&A/Chat
13:00-14:30 Mauro Chase the Optimizer Every Step of the Way
14:30-15:00 All Speakers Panel: What Will Change in the Next 10 Years

 

Thanks guys for organizing such a great ending of the week. You are the best!

ASM: Process PPAx holds disk from being dropped

So I was trying to remove some no longer needed disks from a cluster: 1st I umounted the disgroups from the other cluster nodes and from the last one I executed the DROP DISKGROUP DG_NAME INCLUDING CONTENTS. Nothing new right, but the SA told me that the disks were still being accessed.

I checked with kfod and kfed and also using asmcmd lsdsk -g –candidate, the disks were there, avaliable to be used in another diskgroup but they were no a part of any diskgroup.

I tried to check using asmcmd lsod but it was not returning anything while using lsop and fuser I was able to see the process that was holding the disks, which was an asm process PPA7:
*the disks that I´m was looking for was from the db5*

ASMCMD> lsod --process ppa
Instance Process OSPID Path
1 oracle@server01 (PPA7) 38908 /dev/mapper/mp_db1_data1p1
1 oracle@server01 (PPA7) 38908 /dev/mapper/mp_db1_data3p1
1 oracle@server01 (PPA7) 38908 /dev/mapper/mp_db1_flash1p1
1 oracle@server01 (PPA7) 38908 /dev/mapper/mp_db1_redos1p1
1 oracle@server01 (PPA7) 38908 /dev/mapper/mp_db1_redos6p1
1 oracle@server01 (PPA7) 38908 /dev/mapper/mp_db1_redos7p1
1 oracle@server01 (PPA7) 38908 /dev/mapper/mp_db2_data1p1
1 oracle@server01 (PPA7) 38908 /dev/mapper/mp_db2_data3p1
1 oracle@server01 (PPA7) 38908 /dev/mapper/mp_db2_flash1p1
1 oracle@server01 (PPA7) 38908 /dev/mapper/mp_db2_redos1p1
1 oracle@server01 (PPA7) 38908 /dev/mapper/mp_db2_redos2p1
1 oracle@server01 (PPA7) 38908 /dev/mapper/mp_db3_data1p1
1 oracle@server01 (PPA7) 38908 /dev/mapper/mp_db3_data6p1
1 oracle@server01 (PPA7) 38908 /dev/mapper/mp_db3_flash1p1
1 oracle@server01 (PPA7) 38908 /dev/mapper/mp_db3_redos1p1
1 oracle@server01 (PPA7) 38908 /dev/mapper/mp_db3_redos2p1
1 oracle@server01 (PPA7) 38908 /dev/mapper/mp_ocrvoting2p1
1 oracle@server01 (PPA7) 38908 /dev/mapper/mp_ocrvoting5p1
1 oracle@server01 (PPA7) 38908 /dev/mapper/mp_ora_data1p1
1 oracle@server01 (PPA7) 38908 /dev/mapper/mp_ora_data2p1
1 oracle@server01 (PPA7) 38908 /dev/mapper/mp_ora_flash1p1
1 oracle@server01 (PPA7) 38908 /dev/mapper/mp_ora_redo1p1
1 oracle@server01 (PPA7) 38908 /dev/mapper/mp_ora_redo2p1
1 oracle@server01 (PPA7) 38908 /dev/mapper/mp_ora_redo3p1
1 oracle@server01 (PPA7) 38908 /dev/mapper/mp_ora_redo4p1
1 oracle@server01 (PPA7) 38908 /dev/mapper/mp_db4_data1p1
1 oracle@server01 (PPA7) 38908 /dev/mapper/mp_db4_data6p1
1 oracle@server01 (PPA7) 38908 /dev/mapper/mp_db4_flash1p1
1 oracle@server01 (PPA7) 38908 /dev/mapper/mp_db4_flash2p1
1 oracle@server01 (PPA7) 38908 /dev/mapper/mp_db4_redos1p1
1 oracle@server01 (PPA7) 38908 /dev/mapper/mp_db4_redos2p1

[oracrs@server01 ~]$ fuser /dev/mapper/mp_db5_redos2p1
/dev/dm-99: 38908
[oracrs@server01 ~]$ lsof /dev/mapper/mp_db5_redos2p1
COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME
asm_ppa7_ 38908 oracrs 270u BLK 253,99 0t0 70663 /dev/mapper/../dm-99

Checking MOS I found some notes like Database Process Hold Locks Dropped ASM Disk (Doc ID 2159941.1) but still would not help me as there was no work around the issue.

So basicly I needed to kill the process but could I? It was a production system and kill ASM processes is not something that one should take lightly.

In the documentation the PPA process is found under the
Parallel Query Slave Process which made my life easier, right? Not really.

How to make sure that killing a process would not make the instance to go down?

There is a script and blog post from Tanel Poder which also helped me , and it is worth the reading,

Oracle Database 19c Enterprise Edition Release 19.0.0.0.0 - Production
Version 19.6.0.0.0

SYS@+ASM1>SELECT indx,ksuprpnm,TO_CHAR(ksuprflg,'XXXXXXXXXXXXXXXX')
FROM x$ksupr
WHERE BITAND(ksuprflg,4) = 4 ORDER BY indx
/ 2 3 4

INDX KSUPRPNM TO_CHAR(KSUPRFLG,
---------- ------------------------------------------------ -----------------
2 oracle@server01 (PMON) E
3 oracle@server01 (CLMN) E
4 oracle@server01 (PSP0) 6
5 oracle@server01 (VKTM) 6
6 oracle@server01 (GEN0) 6
7 oracle@server01 (MMAN) 6
13 oracle@server01 (PMAN) 6
15 oracle@server01 (LMON) 6
16 oracle@server01 (LMD0) 6
17 oracle@server01 (LMS0) 6
20 oracle@server01 (LCK1) 6
21 oracle@server01 (DBW0) 6
22 oracle@server01 (LGWR) 6
23 oracle@server01 (CKPT) 6
24 oracle@server01 (SMON) 6
25 oracle@server01 (LREG) 6
27 oracle@server01 (RBAL) 6
28 oracle@server01 (GMON) 6
31 oracle@server01 (IMR0) 6
32 oracle@server01 (LCK0) 6
38 oracle@server01 (ASMB) 6

Cutting the sotry short as my process was not the query output, I did some other testing and I was comfortable enough to kill it and release the disks to the SA team.

Hope it helps

Elisson Almeida

Exadata: Cell Server Crashing on ORA-00600: [LinuxBlockIO::reap]

Hi all,

So I started facing this in a client environment. Here is the alert message:

Target name=db01cel08.xxx.com
Message=ORA-00600: internal error code, arguments: [LinuxBlockIO::reap], [0x60000D502388], [], [], [], [], [], [], [], [], [], []
Event reported time=Dec 19, 2019 2:14:16 AM EDT

When checking on the cellserver I see this message:

[root@db01 ~]# ssh db01cel08
Last login: Thu Dec 19 04:45:13 2019 from db01.xxx.com
[root@db01cel08 ~]# cellcli
CellCLI: Release 12.1.2.3.5 - Production on Fri Dec 19 17:13:31 EDT 2019

Copyright (c) 2007, 2016, Oracle. All rights reserved.

CellCLI> LIST ALERTHISTORY detail

[...]

name: 10
alertDescription: "ORA-07445: exception encountered: core dump [__intel_new_memset()+62] [11] [0x000000000] [] [] []"
alertMessage: "ORA-07445: exception encountered: core dump [__intel_new_memset()+62] [11] [0x000000000] [] [] []"
alertSequenceID: 10
alertShortName: ADR
alertType: Stateless
beginTime: 2019-12-19T02:00:04-04:00
endTime:
examinedBy:
notificationState: 1
sequenceBeginTime: 2019-12-19T02:00:04-04:00
severity: critical
alertAction: "Errors in file /opt/oracle/cell/log/diag/asm/cell/SYS_112331_170406/trace/cellofltrc_19796_53.trc (incident=25). Diagnostic package is attached. It is also accessible at https://db01cel08.xxx.com/diagpack/download?name=db01cel08_2019_12_19T02_00_04_10.tar.bz2 It will be retained on the storage server for 7 days. If the diagnostic package has expired, then it can be re-created at https://db01cel08.xxx.com/diagpack"

name: 11
alertDescription: "ORA-00600: internal error code, arguments: [LinuxBlockIO::reap], [0x60000D502388], [], [], [], [], [], [], [], [], [], []"
alertMessage: "ORA-00600: internal error code, arguments: [LinuxBlockIO::reap], [0x60000D502388], [], [], [], [], [], [], [], [], [], []"
alertSequenceID: 11
alertShortName: ADR
alertType: Stateless
beginTime: 2019-12-19T02:00:04-04:00
endTime:
examinedBy:
notificationState: 1
sequenceBeginTime: 2019-12-19T02:00:04-04:00
severity: critical
alertAction: "Errors in file /opt/oracle/cell/log/diag/asm/cell/db01cel08/trace/svtrc_9174_12.trc (incident=25). Diagnostic package is attached. It is also accessible at https://db01cel08.xxxx.com/diagpack/download?name=jdb01cel08_2019_12_19T02_00_04_11.tar.bz2 It will be retained on the storage server for 7 days. If the diagnostic package has expired, then it can be re-created at https://db01cel08.xxx.com/diagpack"

name: 12_1
alertDescription: "A SQL PLAN quarantine has been added"
alertMessage: "A SQL PLAN quarantine has been added. As a result, Smart Scan is disabled for SQL statements with the quarantined SQL plan. Quarantine id : 21 Quarantine type : SQL PLAN Quarantine reason : Crash Quarantine Plan : SYSTEM Quarantine Mode : FULL_Quarantine DB Unique Name : XPTODB Incident id : 25 SQLID : 8j0az9sgxs5yh SQL Plan details : {SQL_PLAN_HASH_VALUE=281152830, PLAN_LINE_ID=9} In addition, the following disk region has been quarantined, and Smart Scan will be disabled for this region: Disk Region : {Grid Disk Name=Unknown, offset=186750337024, size=1M} "
alertSequenceID: 12
alertShortName: Software
alertType: Stateful
beginTime: 2019-12-19T02:00:12-04:00
examinedBy:
metricObjectName: QUARANTINE/21
notificationState: 1
sequenceBeginTime: 2019-12-19T02:00:12-04:00
severity: critical
alertAction: "A SQL statement caused the Cell Server (CELLSRV) service on the cell to crash. A SQL PLAN quarantine has been created to prevent the same SQL statement from causing the same cell to crash. When possible, disable offload for the SQL statement or apply the RDBMS patch that fixes the crash, then remove the quarantine with the following CellCLI command: CellCLI> drop quarantine 21 All quarantines are automatically removed when a cell is patched or upgraded. For information about how to disable offload for the SQL statement, refer to the section about 'SQL Processing Offload' in Oracle Exadata Storage Server User's Guide. Diagnostic package is attached. It is also accessible at https://db01cel08.xxx.com/diagpack/download?name=db01cel08_2019_12_19T02_00_12_12_1.tar.bz2 It will be retained on the storage server for 7 days. If the diagnostic package has expired, then it can be re-created at https://db01cel08.xxx.com/diagpack"

CellCLI>

After some research, we could match the situation to Bug 13245134 – Query may fail with errors ORA-27618, ORA-27603, ORA-27626 or ORA-00600[linuxblockio::reap_1] or ora-600 [cacheput::process_1]

It’s also described as per: Exadata/SuperCluster: 11.2 databases missing fix for the bug 13245134 may lead to cell service crash with ora-600 [linuxblockio::reap_1]/ora-600 [cacheput::process_1] or ORA-27626: Exadata error: 242/Smart scan issues on the RDBMS side

In order to resolve the crashes quickly, I applied the patch online with:

After applying, all got solved:

[oracle@db01 ~]$ /oracle/xptodb/product/11.2.0.4/OPatch/opatch lsinventory -OH $ORACLE_HOME | grep 13245134
Patch (online) 13245134: applied on Thu Dec 19 23:34:50 EST 2019
13245134
[oracle@db01 ~]$

Hope it helps!

Automatic Killing Inactive Sessions with Resource Manager

Hello All!

So, your are manually (or via script) killing idle sessions on your database?

As consequence, your users are getting error “ORA-00028: your session has been killed.” and getting angry on you?

What about doing it automatically in a much more graceful way and be seen as a nicer DBA? You can do it using Resource Manager.

Are you already using Resource Manager on your database? Yes – Great!

No – Shame on you. Read this and put RM in place ASAP. This is a great tool for the database to manage the database resources, plus no additional licensing is needed. So go for it!

Ok, but what is the trick?
It’s the limit max_idle_time. You can use it either on existing groups or subgroups of your plan (or subplan) or switch to “KILL” groups with this you can even use the same criteria you’d use for any script to perform this action. For this you might user the parameter new_switch_group and have a created a different group only for those kills.

Have this option it’s nicer, if you want to avoid killing sessions on database, by the way, as you can always switch a session for the killing group manually, not demanding it to fill the requirements to automatic switching.

How? Quick example:

Creating new Plan Groups with MAX_IDLE_TIME:

begin
dbms_resource_manager.create_plan_directive( plan => '&RM_PLAN', group_or_subplan =>
'LONG_RUN', comment => 'Limit idle time to 5 minutes', max_idle_time => 300);
dbms_resource_manager.create_plan_directive( plan => '&RM_PLAN', group_or_subplan =>
'SHORT_RUN', comment => 'Limit idle time to 1 minute', max_idle_time => 60);
end;
/

Cool!

And what would be the error for the user that get’s the session killed?

ORA-3113 End of file on communication channel

Much nicer: Now you are a nice DBA and don’t kill sessions anymore.
You automated it!

Some additional recommendations:

  • Use this solution for Databases above 11.2.0.4 or 12.1.0.2, due some known bugs:
    • Bug 9523768 – IDLE SESSIONS AREN’T ACTUALLY KILLED IMMEDIATELY (affecting 11.2.0.1 to 11.2.0.3)
    • Bug 13837378 – ALTER SYSTEM KILL SESSION IMMEDIATE DOES NOT KILL QC SESSIONS (11.2.0.1 to 12.1.0.1)
    • Bug 8891495 – NON-IDLE SESSIONS ARE KILLED (11.2.0.1 only)
  • Some MOS references on it:
    • How To Automatic Kill Inactive Sessions using Resource Manager (Doc ID 1935739.1)
    • Using Resource Manager to Detect and Kill Idle Sessions (Doc ID 1557657.1)

Hope it helps!

Advise: Setting underScore/Hidden Parameters

Please be aware no hidden parameters (parameters starting with “_”) should not be set unless recommended by Oracle explicitly or in case of a perfect match to the case.

This is explained on MOS Best Practices and Guidelines for Setting underScore/Hidden Parameter to Workaround and/or Resolve Customers Problems (Doc ID 2524119.1)

So, in case of any diagnostics you have to lead to setting it, SUGGESTED:

  • Get the explicit approval/agreement from Oracle.
  • Include evidence on the root cause for this setting. A comment should work, something like:
alter system set "_replace_virtual_columns"=false Comment= 'Workaround Doc ID 1512347.1' SID= '*' scope= both;

Cheers!

ORA-20001: Statistics Advisor: Invalid task name for the current user

Hi all,
So, I start seeing on my alert log:

2019-12-26T00:42:03.543268-05:00
Errors in file /u01/app/oracle/diag/rdbms/cdb1/CDB1/trace/CDB1_j000_89793.trc:
ORA-12012: error on auto execute of job "SYS"."ORA$AT_OS_OPT_SY_36807"
ORA-20001: Statistics Advisor: Invalid task name for the current user
ORA-06512: at "SYS.DBMS_STATS", line 47207
ORA-06512: at "SYS.DBMS_STATS_ADVISOR", line 882
ORA-06512: at "SYS.DBMS_STATS_INTERNAL", line 20059
ORA-06512: at "SYS.DBMS_STATS_INTERNAL", line 22201
ORA-06512: at "SYS.DBMS_STATS", line 47197

After some research I found Bug 22879263 – BETA 12.2 – ORA-12012 , ORA-20001 AND ORA-06512 FROM ORA$AT_OS_OPT_SY_88 JOB.

This was suppose to be fixed on 12.2.0.1, however I’m still getting. Anyway, I executed the below and it got fixed:

EXEC dbms_stats.init_package();

Ref: Recurring ORA-12012, ORA-20001, ORA-06512 In Container Database (Doc ID 2420581.1)

Hope it helps!

ODA Useful Commands to Manage VMs

1. To restart the vm:

oakcli stop vm [vm-name]
oakcli stop vm [vm-name] -force
oakcli start vm [vm-name]

2. To show All vm status

oakcli show vm

Example:

root@server oak]# oakcli show vm

NAME NODENUM MEMORY VCPU STATE REPOSITORY
vm1 1 8192 4 ONLINE fileshare

3. Listing Configured Options for a VM Template

oakcli show vmtemplate ol6linux_64

4. Adding a Network to the VM Template

oakcli modify vmtemplate ol6linux_64 -addnetwork net1

5. Configure CPU, Memory on the Template

oakcli configure vmtemplate ol6linux_64 -vcpu 4 -maxvcpu 8 -cpucap 10 -memory 3000M -maxmemory 6G -os OTHER_LINUX

6. Create a VM by Cloning from Template

oakcli clone vm ol6test -vmtemplate ol6linux_64 -repo repo1 -node oda2

7. Override VM Template Values

oakcli configure vm ol6test -vcpu 6 -memory 4G

8. Configure High Availability and Failover Values

oakcli configure vm ol6test -prefnode oda2 -failover oda1

9. Start a VM

oakcli start vm ol6test

10. Access VM Console for a VM:

oakcli show vmconsole [vm-name]

Hope it helps you!