Most of you know I don’t like pink, but I also am not a fan of yellow. Yellow houses Yellow flowers Yellow in my EM12c summary page You know what yellow I’m talking about: Now I’m just as disturbed by the red section of that graph, but today, we’re going to focus on the unknown, the yellow. If something is down, then you know it isn’t uploading data and is most definitely a critical issue, but what about the unknown? Why is Enterprise Manager reporting something is unknown? To first tackle this type of summary, we need to know the…
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I’m often asked what management pack is used by what feature and there is actually a very easy way to find out this information in the EM12c console. Let’s say we are in ASH Analytics and want to view what management packs are required as part of this feature utilization: Click on the global Setup menu in the upper right, then click on Management Packs and Packs for this Page– You will quickly see a pop up page that shows you what management pack(s) are required to use the ASH Analytics feature: If we jumped to SQL Monitor and did…
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So back at the end of the EM CAB, I’d received an email stating I had an over-sized database and too many hits to continue on Go Daddy as the host for my website. I called into tech support to understand what options I had, but was never told that I had any option but leaving Go Daddy as my hosting service. I was told I had two weeks per the email, but asked for three and was told on the phone that wasn’t a problem. I then did some research and decided that Blue Host had done well supporting…
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Every so often a DSS query that usually takes 10 minutes ends up taking over an hour. (or one that takes an hour never seems to finish) Why would this happen? When investigating the DSS query, perhaps with wait event tracing, one finds that the query which is doing full table scans and should be doing large multi-block reads and waiting for “db file scattered read” is instead waiting for single block reads, ie “db file sequential read”. What the heck is going on? Sequential reads during a full table scan scattered read query is a classic sign of reading…
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What happens with I/O requests over NFS and more specifically with Oracle? How does NFS affect performance and what things can be done to improve performance? What happens at the TCP layer when I request with dd an 8K chunk of data off an NFS mounted file system? Here is one example: I do a dd if=/dev/zero of=foo bs=8k count=1 where my output file is on an NFS mount, I see the TCP send and receives from NFS server to client as: (the code is in dtrace and runs on the server side, see tcp.d for the code) There is a lot…
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What is right deep verses left deep? Good question. In join trees (not VST) the object on the left is acted upon first then the object on the right. Below are left deep and right deep examples of the same query, showing query text join tree join tree modified to more clearly show actions VST showing the same actions All of this boils down to the point that a right deep HJ can return rows earlier than a left deep HJ. A left deep HJ has to wait for each join to finished completely so that the result set can be hashed before the next…
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We are back to REPVFY, (Repository Verification Utility) this week, (first post can be found here…) And I’m onto the next file of substance since looking at the advisor log, (performance data). The next files are the two “details” files. One is a query used to produce the output and the second is the actual output from it. These two files are clearly named and can be found with the following naming convention: details_<timestamp>.sql details_<timestamp>.log If you are curious about what the details_<timestamp>.sql is doing as it produces the output, well you’re in luck, as I’m going to go step…
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When working with Top Activity, we’re accustomed to viewing to wait class in the top, graphed area and below left, the top SQL by SQL_ID and below right is our Top Session information. ASH Analytics was designed so you would enter into a view that looked very similar to Top Activity, but was enhanced so the user could update it to view the data in multiple ways. In Enterprise Manager’s traditional view of Top Activity, it is easy to recognize the similarities with ASH Analytics but that’s where much of it stops. The user has the ability to change not just the…
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About year ago or more, Oracle came out with a way to create thin clone copies of a database in EM 12c called “Snap Clone”. Not sure this makes working with data any sunnier and certainly doesn’t add any sunlight to the cloud movement. Snap Clone technology has seen little adoption AFAIK. I’m not aware of a single customer reference yet, besides internal usage at Oracle. Why ? Because Snap Clone doesn’t solve the real problem. Snap Clone is complex, depends on cobbling other technologies together, and lacks in crucial features. The real solution is simplicity and end-to-end integration with data source syncing all…
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The last couple weeks I’ve been lucky enough to get time with a new ZFSSA Simulator, (it will be out soon for everyone, so you’ll have to just play with the current one available, patience grasshopper! :)) and spent checking out the newest features available with Database as a Service, (DBaaS) Snapclone via Enteprise Manager 12c. I’m really thrilled with Snapclone- In two previous positions, I spent considerable time finding new ways of speeding up RMAN duplicates to ease the stress of weekly datamart builds that were sourced off of production and this feature would have been a lifesaver back…
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Performance testing requires full, fresh data Many organizations don’t even attempt to test performance until very late in their development cycle because it is only in the UAT (or equivalent) environment that they have a full copy of their production data set. Errors and inefficiencies found at this stage are expensive to fix and are often promoted to production due to pressures from the business to meet release schedules. Delphix customers give each developer, or team of developers, a full, fresh copy of the database where they can validate the performance of their code in the UNIT TESTING phase of…
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This is the first of many posts I’ll do where we take a particular issue and trouble-shoot. I’ll go through multiple scenarios to show the common steps to take via the Enterprise Manager 12c from discovery to identification to research to explanation. This blog will use the following features: ASH Analytics SQL Details ASH Report The first thing we need is an issue- Note the CPU red line- the IO is considerably over that and quite a lot of IO, along with Commit and Concurrency waits. We’ll start with this as our issue that we can see, has quickly escalated…
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There are a number of Verification Utilities for Enterprise Manager 12c, (EM12c) and I’ve written about them before, but today I’m going to start on the Repository Verification Utility, (REPVFY). This will be an ongoing series, as there are so many valuable features rolled into the utility and new ones that will be added as new patches and releases happen. For this post, I’m going to be reviewing a level 2 diagnostics report from a new repository database. This is going to offer us all kinds of valuable data about the environment and should be considered by any EM12c administrator…
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Now that we learned in Part I how to create a notification schedule for a specified user so that it will only page one individual on an oncall rotation, I’ll now show you how to use this in conjunction with rulesets to complete the process of modernizing and automating your oncall. In my Test scenario, I’ve already made copies of the main rule sets, have deviated rules by three rules and four groups, (mission critical, production, test and development.) Mission critical are all systems that I WANT to be paged for after hours and need to know immediately if there…
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I came across a discussion on Oracle-l on how after hours paging was handled for many companies and was kind of surprised how many DBAs still carry around a secondary pager/cell phone or are just expected to be woke up if on call or not. I’m not one to go back to sleep once I’m woke, so I’ve been a proponent of EM notification schedules for after hours paging. Now there are other ways to handle this in Enterprise Manager 12c as well, but we’ll use this method, as it is backward compatible to OEM 10g, too. The requirement of…
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Followup: The tweets from the datachat are available at http://www.confio.com/logicalread/oracle-db-performance-80-percent-hardware-dc01/ in chronological order. Confio software is hosting a live discussion on twitter tomorrow Tuesday April 15 at 12pm PST on the subject of Oracle performance. I’ll be online answering performance questions and have invited many other friends to participate. Some friends who’ve said they’ll be there are Arup Nanda Dominic Delmolino Marcin Przepiorowski Toon Koppelaars Karl Arao Participation and tracking of the discussion can accomplished by either posting with and following along with the #datachat hashtag. Get on TweetDeck or your favorite Twitter tool, search #datachat, add a column and…
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Lately I’ve been having more discussions on securing the EM12c environment. All of IT has a tendency to treat the Enterprise Manager as a afterthought in both hardware allocation, as well as security best practices. No one is sure of exactly why this is- they all have their theories, but we do know it happens often. Today we are going to go over some of the auditing options within EM12c. Basic auditing is turned on by default in the environment, but only covers basics processes. There are over 150 auditing options and extensive information can be collected, retained within the…
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Maximum manageable storage per VM by ESX version 4.1: 32TB (vmdk) / 120TB (RDM) 5.0: 60TB (vmdk) / 3.75PB (RDM) 5.1: 60TB (vmdk) / 3.75PB (RDM) 5.5: 3.63PB (vmdk) / 3.75PB (RDM) Note that the 60TB limit for 5.0 and 5.1 requires Update 1. Without this the limit is 24TB. Exceeding the limits on ESX < 5.5 can result in VMFS heap exhaustion and data corruption! More details: Component ESX 3.5 * ESX 4.0 ESX 4.1 ESX 5.0 ESX 5.1 ESX 5.5 vCPUs 4 8 8 32 64 64 RAM 64GB 255GB 255GB 1TB 1TB 1TB Disk Size (VMDK)…