Showing posts with label Architecture. Show all posts
Showing posts with label Architecture. Show all posts

Sunday, July 10, 2011

SharePoint 2010 - Search Error - The search service is not able to connect to the machine that hosts the administration component

Problem:


We recently ran across an issue that prevented the SharePoint Server 2010 from starting with the below exception:

"The search service is not able to connect to the machine that hosts the administration component"


When I clicked on any link in the left navigation in search administration interface inside Central Administration, I was greeted with the below exception:


The application pool in IIS that the search service uses is found in stopped state. It stops automatically as soon as it is started.



Explanation:

After hours of research, we have found that it was all happening due to an AD policy set in domain controller that was not allowing certain service accounts from being able to start services and application pools

Here are the steps we followed to fix this issue:

  • First we did a complete rebuild including the OS
  • Then the search service worked but a service account was not able to start search service and the Web Services Default App Pool.. (sp2010sa account in our case)
  • We then updated the group policies in AD to allow the service accounts to have "logon as a batch" job rights
  • We had a problem in pushing the group policy to client(s). For that change to take place in the servers in the domain, we had to take the servers out of the domain and re add them..
  • So we removed computer(s) from domain, computer account was not created in the correct Organizational Unit(OU). New policy was forced as an update on the computer. So we removed the computer from the domain and rejoined to the domain..
  • In this process SharePoint Config DB got corrupted and so CA was gone
  • So we uninstalled SP 2010 again, removed all the SP databases and re-installed SP 2010

Summary:

In short, before installing SharePoint, make sure that you follow the least privileged approach and create all required service accounts. This article here  describes it very well.

Make sure that the managed accounts used such as SharePoint Search, SharePoint App Pool and the SharePoint Farm Account have "logon as a batch" job rights.

Server(s) can be removed from domain but computer accounts should not be removed. If computer account(s) are removed, the identifier(s) will be deleted and therefore the identifiers change the next time when the servers are added again to the domain controller. SharePoint looks for the identifiers in config database and since it could not find the correct identifiers, CA would not work.

If you have to apply new policy such as "logon as a service", make sure to place the computer(s) in correct Organizational Unit(OU) and remove the computer(s) from domain. The policy is then reset and it assigns the correct "logon as a service" credentials.

This wont be the case in most installations.
In our case, we ran into issues due to incorrect / corrupt AD structure / domain controller.

I am not a network specialist but if there is a way to ensure that all the AD group policies are being applied properly prior to installing SharePoint, you would save yourself from the above mentioned hassles.

Saturday, January 8, 2011

How to estimate the storage space required for SharePoint 2010 content databases and Index servers?

Scenario:
How to estimate the storage space required for SharePoint 2010 content databases and index servers?

Explanation:

The following process describes how to approximately estimate the storage required for content databases, without considering log files:
1.   Calculate the expected number of documents. This value is referred to as D in the formula.

How you calculate the number of documents will be determined by the features that you are using. For example, for My Site Web sites or collaboration sites, we recommend that you calculate the expected number of documents per user and multiply by the number of users. For records management or content publishing sites, you may calculate the number of documents that are managed and generated by a process.

If you are migrating from a current system, it may be easier to extrapolate your current growth rate and usage. If you are creating a new system, review your existing file shares or other repositories and estimate based on that usage rate.
2.   Estimate the average size of the documents that you will be storing. This value is referred to as S in the formula. It may be worthwhile to estimate averages for different types or groups of sites. The average file size for My Site Web sites, media repositories, and different department portals can vary significantly.
3.   Estimate the number of list items in the environment. This value is referred to as L in the formula.

List items are more difficult to estimate than documents. We generally use an estimate of three times the number of documents (D), but this will vary based on how you expect to use your sites.
4.   Determine the approximate number of versions. Estimate the average number of versions any document in a library will have (this value will usually be much lower than the maximum allowed number of versions). This value is referred to as V in the formula.

The value of V must be above zero.
5.   Use the following formula to estimate the size of your content databases:

Database size = ((D × V) × S) + (10 KB × (L + (V × D)))

The value of 10 KB in the formula is a constant that roughly estimates the amount of metadata required by SharePoint Server 2010. If your system requires significant use of metadata, you may want to increase this constant.
As an example, if you were to use the formula to estimate the amount of storage space required for the data files for a content database in a collaboration environment with the following characteristics, you would need approximately 105 GB.
Input
Value
Number of documents (D)
200,000
Calculated by assuming 10,000 users times 20 documents
Average size of documents (S)
250 KB
List items (L)
600,000
Number of non-current versions (V)
2
Assuming that the maximum versions allowed is 10
Database size = (((200,000 x 2)) × 250) + ((10 KB × (600,000 + (200,000 x 2))) = 110,000,000 KB or 105 GB

Microsoft recommends 80 GB of hard disk space for WFE servers. Maintain twice as much free space as you have RAM for production environments.

A quick formula to calculate the hard disk space on the index server would be to multiply the expected index-able content by 20%.

So for example if the expected total content to be indexed is 500 GB, the index server needs at least 500 * 20% = 100GB

This white paper from Microsoft explains how to estimate performance and capacity requirements for SharePoint in more detail. (page 45 for specific guidance on how to calculate storage needs for search)