“The maximum number of allowed sessions per user has been exceeded. This operation cannot be completed” Error in SharePoint Excel services

While working with SharePoint Excel chart and graphs I got an error saying that “The maximum number of allowed sessions per user has been exceeded. This operation cannot be completed” as shown the image below.

We can get this error maximum sessions limit exceeded. By increasing the Maximum Session Per user limit, we can fix this error. We can increase the Maximum Sessions Per User by using the steps below,

Navigate to Application Management page and click on Manage Service Application link in Service Applications section. 

Click on Excel Service application in the list of service applications

 In Manage Excel Services Application page, click on “Global Settings” link

In Excel Services Application Settings page, “Session Management” section, enter Maximum sessions Per User. By default it is 25.  

Sharing SQL Server Analysis Service connection using SharePoint 2013 Excel Services

In my previous post, I have explained sharing SQL Server Data source connections in SharePoint 2013. In this post we can use SQL Analysis service connection. We can create Analysis service connection as shown the steps below,

In Excel, Data tab,  click on From Other Sources and select From Analysis Services option.

In Connect to Analysis services, in the Server name box, we have to specify the SQL Server name to get the SQL Server data. Here Iam entering as “.” to connect the local. We have to specify the Log on credentials in the credentials section. To use Windows Authentication, we have to select Use Windows Authentication or to choose SQL Server authentication Select SQL Server Authentication and have to enter the credentials. Click on Next.

“In the Select the database that contains the data that you want” list; we have to select the database that we want to use. If we don’t want to select any database or if there is no databases, uncheck Connect to a specific table.

On Save Data Connection and File and Finish page, we have to enter File Name, Description, Friendly Name, and Search Keywords boxes. In the Authentication settings, we can choose the type of authentication. Click on finish.

Connection will be saved in default location. Once we save the connection, we can upload the connection file Data connections library as shown in my previous post.

Sharing SQL Server Data source connection using SharePoint 2013 Excel Services

We can connect different data sources using excel services includes SharePoint list, access DB, Windows azure etc... All the data connections in excel will support in excel services. We can refresh the data in excel service reports and dashboards and also supports SQL server tables and Analysis services cubes and OLE DB data providers. We can also save the connections to excel services trusted data connection library. It will help us to access the data sources easily without knowing server names and DB names. Excel service workbooks uses in a trusted data library to easy access the current information.

We can use Excel to create and share connections with database. When uploading a data connection to excel services trusted data connection library, data connections will be available to use data models, reports and score cards. Depending on the data source, data will be refreshed easily in excel service workbooks.

To create a SQL server tabular data connection by using excel, we have to follow the steps below,

In Excel Data tab, click on From Other Sources in Get External Data group and we have to select SQL Server.

In Connect to Database Server page, Server name box, we have to specify the SQL Server name to get the SQL Server data. Here Iam entering as “.” to connect the local. We have to specify the Log on credentials in the credentials section. To use Windows Authentication, we have to select Use Windows Authentication or to choose SQL Server authentication Select SQL Server Authentication and have to enter the credentials. Click on Next.

“In the Select the database that contains the data that you want” list, we have to select the database that we want to use, In the Select Database and table page, To create new connection uses single table, we have to select Connect to specific table and we need to select the table to use. By selecting Enable selection of multiple tables, we can select multiple tables.

On Save Data Connection and File and Finish page, we have to enter File Name, Description, Friendly Name, and Search Keywords boxes. In the Authentication settings, we can choose the type of authentication. Click on finish.

On Import Data page, Click on Only Create Connection and Click on OK. 

To Upload Data connections to SharePoint,

Navigate to BI center site and Open Data Connections Library.Click on New Item and click on Browse to choose the file.

If we save the data connections in Default location, in default location, click on libraries, Documents and navigate to My Data Sources.

Select the ODC file that we wanted to upload and click on Open.

In the Add a document dialog box we have to select Content Type as Office Data Connection File. Need to provide details for Name, Title and Description and Keywords, click on Save. 

New data connection will be added as shown below.

Wow that’s big workbook. Unfortunately we can’t open a workbook larger than 10MB. You’ll need to open this in Excel - Large workbook error in SharePoint Excel Services

While working with excel workbooks in SharePoint, I got an error saying that, “Wow that’s big workbook. Unfortunately we can’t open a workbook larger than 10MB. You’ll need to open this in Excel.”

After checking issues into deep, found that the reason for this error is the size of the workbook to be opened is larger than the maximum size of workbook. We can configure the maximum size in the excel services settings.

To change the value, Navigate to Application Management, select Manage Service Applications link.

Select Excel Service application to configure to configure maximum value.

Click on Trusted File Locations in Manage excel service applications page

We’ll be navigated to Excel Services Application Trusted File Locations. Click on specific address we need to configure maximum size.

In Excel Services Application Edit Trusted File Location page, Workbook properties section, we have to specify the Maximum Workbook Size as per our need, click on OK 

button. 

“An error occurred during an attempt to establish connection to external data source…” error in SharePoint Excel service PivotTable manual refresh

In SharePoint server 2013, to refresh the data manually in PivotTables need to go for Data -> Refresh All Connections as shown in the image below.

While refreshing data I got an error like “An error occurred during an attempt to establish connection to external data source…” 

After checking the error in Logs I have find that the issue with identity currently set. When we access to refresh the data in PivotTables Claims to windows token service (C2WTS) will be used. If C2WTS is running with domain account that domain account needs permissions on the SharePoint server where it is running.

C2WTS domain account must be in SharePoint server’s local administration group where it is running and it has to impersonate the client after the authentication, Works to log an as service and it needs to be act as part of the operating system.

To access the local security policy of the server, Go to Administrative Tools -> Local Security Policy -> Local Policies -> User Rights Assignments

By adding the permissions to the account that running Claims to windows token service, we need to restart the service on each server it is running. 

Configuring Excel Services in SharePoint 2013 - II

In my earlier post, I have mentioned configuring excel services Global settings and Trusted file location. In this post we can see trusted data providers, trusted data connection libraries, user defined function assemblies and data model settings.

Trusted data providers works as data providers for excel services to access the data. A data provider is a protocol that combined with database type for accessing data. By default excel services will not access data without trusted data providers. Excel services will contain the data providers as entries. We have to add additional data providers as per our requirement.

By clicking on the trusted data providers link in Manage Excel Service Application Page, we will navigate to Excel Services Application Trusted Data Providers page. We can see a list of trusted data providers from excel service. To add new data provider, click on “Add Trusted Data Provider” link on the top of the page.

On the Excel Service Application Add Trusted Data Provider page, Provider section, we need to add the provider ID in Provider ID text box. In the Provider Type, we have to select the one of the following options, OLE DB, ODBC, ODBC DSN. OLE DB option will access the data by using Object Linking and Embedding. By selecting ODBC option, data will be accessed using Open Database Connectivity. By selecting the ODBC DSN, data will be accessed using Open Database Connectivity with Data Source Name.

To Configure trusted data connection libraries for excel services click on Trusted Data Connection Libraries in Manage Excel Service Applications page. Trusted data connection libraries are the data connection libraries for trust configuration in SharePoint 2013 excel services. All the Data connections for excel services will stored in trusted data connection library.

To create new trusted data connection in SharePoint 2013 excel, Click on Add Trusted Data Connection Library in Excel Service Application Trusted data Connection Libraries page.

We will navigate to Excel Service Application Add Trusted Data Connection Library page. In the Location section, we need to enter the document library URL that permit to access the excel service application. We have to add the description of the trusted data connection in the description text box.

To add the User defined assemblies for the excel service, click on User Defined Function Assemblies link in Manage Excel Services Application page. Click on Add User-Defined Function Assembly button on the page to add new User-Defined Assembly.

In the Excel Service Application Add User-Defined Function Assembly page, Assembly details section, enter the Assembly strong name or path of the assembly contains the user-defined function. Depending on the Assembly type you have entered, select the option Global Assembly Cache or File path. Check Assembly enabled check box to allow the user-defined function assembly to be located and used by Excel calculation service. Unchecking this option, disables the option assembly will not be added for user defined function.

In SharePoint 2013 Excel Services, We can specify the SQL server instances for Analysis services to process the data models. This will provides the backend services for Excel service to load query and refresh the data model. To add the instance of the SSAS, we must have to install the Power Pivot for SharePoint mode. We can add new data model in SharePoint excel service in Excel Services Application Data Model Settings page. By clicking on the Add Server button, we will navigate to Excel Services Application Add Server page to add new data model.

In the Excel Services Application Add Server page, Server section, we have to enter the instance of SQL Server 2012 SP1 Analysis Services (SSAS) Server Name to add the new data model. Description is optional that helps to describe the data model setting.

We can deploy the excel services in three scenarios, Enterprise, Medium or small department and custom. While configuring the enterprise scenario we have to check that, don’t configure support for User defined functions, do not enable workbooks to use embedded data connections or direct access of external data. Need to limit the usage of data connection libraries from external Data source access. For small department deployment, we have to enable the trust for all the locations using the department members. Need to enable the trust children option for all the trusted sites and directories. If any chance to get problems from a file location, just restrict the access. In custom deployment, enable the excel services to open the large work books, we need to configure the long session time-out and large data caches that there is change to delay in the connection. Here we don’t enable the trusted child for trusted location and need to create a single trusted location. 

Configuring Excel Services in SharePoint 2013

In my previous post, I have explained how to create excel service. In this post we can see how to Manage the excel service application. By navigating to manage excel service application page, we can see six links, allows us to manage the service application.

By clicking on the Global Settings link, we will be redirected in to Excel Service Application settings page. This includes settings for Security, Load Balancing, External Data, Memory utilization and Workbook cache.

Security settings will gives the options for excel service application authentication, communication and service settings. File Access method for excel services will have two options Impersonation and Process account. Impersonation enables a thread to run in a security context that owns the thread. We need to select the Impersonation, when workbooks are stored in http locations. Process account option need to be used when excel services opens the work books from HTTP sites. In the Connection Encryption section, we need to use Internet Protocol Security or Secured Sockets Layers (SSL) to encrypt the data transmission. There no need of connection encryption by default. But if we choose the require connection encryption option, excel service application server enable data transmission between the client computer and front-end web servers.

Load Balancing settings allows us to maintain the sessions across the excel calculation 

services process.

Session Management settings allow us to set maximum number of sessions allowed per user.

Memory Utilization settings will gives the options to allocate the memory on the excel services.

By using Workbook cache settings, we can set the caching workbook files on the disk and in memory.

Through external data settings, we can handle the external data connections in excel calculation services.

“Trusted File Locations” in Excel services, trusts the entire SharePoint farm. In SharePoint, by default we have a trusted file location (http://) enables any file to be loaded from SharePoint server farm or stand-alone deployment. By trusting the whole SharePoint farm enables the easier setup for the administrators. For security purpose we can create new trusted file locations. Trusted file locations may be SharePoint sites or http sites that running the excel services that allows accessing workbooks.To add the new trusted location, Click on the “Trusted Locations” link, we can see Excel Services Application Trusted File Location page. Click on “Add Trusted File Location” link on the top of the page.

In the Address text box, we need to specify the location of the excel documents that excel services trust. We have to specify the type of the address in the location type like SharePoint or network file share or HTTP. If we want to trust the all children for that location, check Children Trusted in the Trust Children section.

In the Session Management settings section Session Timeout field specifies the maximum time that excel calculation service open/active. We can measure the session timeout that request time to reach start to end. The default session tome out is 300 sec. Short session timeout specifies the maximum time that excel web access service open/active. This is similar to session time-out setting. Default value is 75 sec. Maximum request duration filed specifies the maximum duration of a single request in a session.

Workbook property settings specify the behavior of the workbooks from specified trusted location in excel calculation services. Here Maximum Workbook size specifies the maximum size of the workbook that can be opened from Excel calculation service. Default value is 10 MB. Maximum chart size specifies the maximum size of the chart that can be opened by excel calculation service. Default value is 1 MB.

Calculation behavior specifies the modes of calculation in excel calculation service. Volatile Function Cache Lifetime field specifies the value for maximum time that computed value for automatic recalculation cache. Default value is 300 seconds. Workbook Calculation mode specifies calculation mode of workbooks in excel calculation service.  Manual, Automatic and Automatic except data table’s settings will override the settings. Default value is File.

External data services specifies how excel calculation services should handle external data connections in workbooks from trusted locations. Allow external data field specifies the external data processing. To disable the external data connection, we have to select radio button None. Trusted data connection libraries or trusted data connections libraries and embedded will allow the connections embedded with trusted location workbooks. Refresh warning enabled will display the warning message before refreshing the external data in workbooks from trusted locations. Default is enabled. Stopping open enabled to stop the open operation on a file from trusted location when the file contains the refresh. Default value is enabled. Automatic refresh (periodic/on-open) specifies automatic refresh duration period. Default value is 300. Manual Refresh field specifies the manual refresh duration. Default value is 300. Maximum Concurrent Queries per Session specifies the value for the number of eastern queries can execute in a session concurrently. Default value is 5.

User-defined functions allowed in the User-defined functions section, allows permitting user-defined functions to call from workbooks from trusted location. Default value is disallowed.