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EM13c: Unauthorized Access to Performance Pages

I noticed an interesting security problem (exploit?) on Oracle Enterprise Manager Cloud Control 13cR2 (I tested on EM13cR1 and it also exists on there). When you create an Enterprise Manager administrator, you need to grant some special privileges to that administrator if you want them to access the performance pages, but it seems there’s an alternative way to access the performance pages without requiring extra privileges.

Let’s say I created a new administrator with default roles (EM_USER and PUBLIC), and granted “Connect Target Read-only” for a target “RAC database”. I also granted access to a named credential or shared database login credentials.

performancemenu

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Oracle Database Cloud Service: Set up Access Rules

I’ve started to test Oracle Database Cloud Services. I applied for trial, it’s accepted (you can also get a trial account, there’s no special requirement for it). After I got my welcome emails, I created a database service. As expected, it was very easy. All I needed is to click a couple of times, enter mandatory information and then wait until my Database is provisioned.

Oracle creates a VM for each database because they provide SSH access to the server. This gives you more power than standard PaaS but I don’t know what happens if you make some modification on the OS level such as upgrading packages, changing kernel settings etc…

Anyway, after I created a Database Service, I wanted to connect to EM but I see that I couldn’t access the page. First, I though it’s a bug, then I remembered our company firewall rules are very strict and it’s related with our firewall, then I noticed that almost all ports (expect SSH) are blocked.

databaseservice

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EM13c: Get List of URLs Monitored by Beacons

When you need to monitor web services, you can use EM beacons. A beacon is a target that allows the EM Agent to remotely monitor services. You can add beacons to any EM agent using “Add Non-Host Targets by Specifying Target Monitoring Properties” option in the Add Targets Manually page. After adding a beacon, you can configure it to fetch a web page and test the status of the service according to the result of the web transaction.

One of my blog reader said that they have a list of URLs and they need to know which beacon server is polling each URL by querying the URL. We need to query four views to get this information: mgmt_targets, mgmt_bcn_target, mgmt_bcn_step_defn, mgmt_bcn_step_props.

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EM13c: Is It Possible to Delete a Job Run with EMCLI?

Enterprise Manager Cloud Control provides a centralized job scheduling system and it’s possible to control it through both web interface and EMCLI. On the other hand, it seems web interface provides more control over the past jobs, for example it’s not possible to delete a job run with EMCLI, while it’s possible to do it on web interface:

deleterun

EMCLI verb “get_jobs” reports all runs of the jobs, and “delete job” can delete job and its all runs but it’s not possible to delete a specific run of a job. For example, if you want to delete hundreds of “failed” (or “skipped”) runs of a job, EMCLI won’t help you and doing it through the web interface will be very time consuming.

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OTN Appreciation Day: Oracle Wait Interface

Thanks to Tim Hall, lots of people from Oracle community, shared their favourite Oracle feature as blog posts. I’ve decided to dedicate my OTN Appreciation Day blog post to Oracle Wait Interface. I know that the topic was not limited to Oracle database, and I could share something about Oracle Enterprise Manager (my main focus area), but Oracle database is the entry point for me and it’s the reason why I started to use other Oracle products (including Oracle Enterprise Manager).

Most of the time, people ask me why I prefer to work with Oracle database. It has great features like having reliable infrastructure, flashback, partitioning, in-memory column store etc. It comes with a great backup and recovery tool (RMAN) and it supports PL/SQL (great way to deal with data). All of these features (and the ones I didn’t count here) helps Oracle database to be the best relational database management system, but when I think about Oracle, the performance monitoring features are my favourite, and Oracle Wait Interface is the foundation stone of those features.

Each time a process waits for something, Oracle collects statistics about the wait. Oracle Wait Interface provides statistics for these waits, and these statistics can be accessed trough a collection of dynamic performance views or an extended SQL trace file. This information is invaluable to monitor sessions and guides you to find the root cause of many performance problems.

For more information about Oracle Wait Interface, you may read: “Oracle Wait Interface: A Practical Guide to Performance Diagnostics & Tuning” book.

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