In Feburary 2016 28,
Oracle servers run both an Oracle database and listener process. One Oracle listener, which you can configure to support multiple databases, receives and manages client connection requests. If the listener receives more requests than it can handle, user requests can time out; in this case, restarting the listener will resolve the error.
Database Connection
Oracle database connection requests aren't processed unless they include authentication information such as a user name, password and the name of the Oracle service. If the authentication services aren't running or the password name is incorrect, communication efforts will fail. Similarly, if the Oracle database locks up and fails to respond to database queries, Oracle will report a failure. According to “Oracle Dba on Unix and Linux” by Michael Wessler, if the Oracle database itself crashes, the program's background processes such as PMON and SMON will terminate, and you will receive an “ORA-12637 packet receive failed” or 'TNS: packet writer failure' message.
Server & Hardware
The Tnsnames.ora file on your computer contains references to Oracle servers with which it regularly communicates. If a server name is incorrect or incomplete, Oracle can't connect to it. If the port referenced in the Tnsnames.ora file isn't open, you may see an “ORA-12637 packet receive failed” message. Router and network interface controller, or NIC, card failures also cause this problem, as can insufficient server disk input/output and system memory.
Communication
Packet communication errors can occur when a network's data traffic is so great that the time-out limit hits before your computer receives a response from the Oracle server. If the packet sizes are too large for the server to process, you can change the transport date unit, or TDU, parameters in the Tnsnames.ora file. If a network router fails and the data packets are routed to other nodes that cannot handle the load, error messages will result. You also might see errors from a malicious denial-of-service attack, or hackers turning off the Oracle listener, although the latter appears as a process failure.
In Feburary 2016 28,
Showing posts with label communication. Show all posts
Showing posts with label communication. Show all posts
Sunday, 28 February 2016
Friday, 26 February 2016
Skills for a Computer EngineerIn Feburary 2016 26,
In Feburary 2016 26,
A computer engineer must have extensive technical skills to design and choose software components for a project. This includes understanding technical language, such as C++, Java, JavaScript, HTML, CSS, SERVLET and UML design. It also includes recognizing the major differences between operating systems like Windows, DOS, Mac and Linux. Some computer engineers also work with computer databases like MySQL, Access and Oracle.
Communication Skills
Communication and interaction is a vital part of a computer engineer's job. He must interact with managers or business owners for company projects or directly with customers, if the computer engineer is working on developing solutions for customers. The computer engineer must communicate the possibilities of the given project budget, update customers or managers on the progress of projects and be able to conduct presentations on the computer development projects.
Research and Training Skills
A computer engineer must also have extensive research and training skills, especially if placed in a managerial position. Computer sciences and possibilities in the information technology and computer industry are constantly evolving and expanding. The computer engineer must be able to research and learn new programming options and skills to provide the best possible outcome for companies or customers. The computer engineer should also be able to train coworkers or employees in these new skills and programming options.
Decision-Making and Troubleshooting Skills
Computer engineers frequently work with the design and development process of computer software on behalf of customers or within a company. The computer engineer must be able to make the best decisions for the program development project in question. This is done by combining the technical skills and knowledge with the demands and needs of the customers or company. If something does not work throughout the design and development process, the computer engineer must also be able to troubleshoot to repair the issues. This can be a clash of software programs or operation systems, for instance. These skills need to be honed for computer engineer manager positions.
In Feburary 2016 26,
A computer engineer must have extensive technical skills to design and choose software components for a project. This includes understanding technical language, such as C++, Java, JavaScript, HTML, CSS, SERVLET and UML design. It also includes recognizing the major differences between operating systems like Windows, DOS, Mac and Linux. Some computer engineers also work with computer databases like MySQL, Access and Oracle.
Communication Skills
Communication and interaction is a vital part of a computer engineer's job. He must interact with managers or business owners for company projects or directly with customers, if the computer engineer is working on developing solutions for customers. The computer engineer must communicate the possibilities of the given project budget, update customers or managers on the progress of projects and be able to conduct presentations on the computer development projects.
Research and Training Skills
A computer engineer must also have extensive research and training skills, especially if placed in a managerial position. Computer sciences and possibilities in the information technology and computer industry are constantly evolving and expanding. The computer engineer must be able to research and learn new programming options and skills to provide the best possible outcome for companies or customers. The computer engineer should also be able to train coworkers or employees in these new skills and programming options.
Decision-Making and Troubleshooting Skills
Computer engineers frequently work with the design and development process of computer software on behalf of customers or within a company. The computer engineer must be able to make the best decisions for the program development project in question. This is done by combining the technical skills and knowledge with the demands and needs of the customers or company. If something does not work throughout the design and development process, the computer engineer must also be able to troubleshoot to repair the issues. This can be a clash of software programs or operation systems, for instance. These skills need to be honed for computer engineer manager positions.
In Feburary 2016 26,
Wednesday, 17 February 2016
Problems Accessing FTP SitesIn Feburary 2016 17,
In Feburary 2016 17,
There are many ways to authenticate to an FTP site, but it requires being an authenticated user. An authenticated user is someone who has been given permission to connect to the FTP site.
Resources
In some cases, authenticated users may not have been given rights to FTP sources. Even if you can access the FTP site, an authenticated user without rights will not be able to view the directory tree.
Firewall
There may be a firewall in place preventing communication to and from the TCP/IP ports. This can be due to Internet security settings that may be incorporated into software such as MacAfee and Norton security programs. Companies and other administrative superiors may have established policies prohibiting access.
Connection Limits
An FTP site may have a limited quantity of available simultaneous connections. If this number is met, further connection attempts will be denied and logged for administrative purposes.
Bandwidth Limit
A bandwidth limit governs how much information can be transferred at a time. If this number is close to being met, the connection will become slower. If the communication between the computer and server exceeds an established duration, the connections will time out, resulting in an error.
In Feburary 2016 17,
There are many ways to authenticate to an FTP site, but it requires being an authenticated user. An authenticated user is someone who has been given permission to connect to the FTP site.
Resources
In some cases, authenticated users may not have been given rights to FTP sources. Even if you can access the FTP site, an authenticated user without rights will not be able to view the directory tree.
Firewall
There may be a firewall in place preventing communication to and from the TCP/IP ports. This can be due to Internet security settings that may be incorporated into software such as MacAfee and Norton security programs. Companies and other administrative superiors may have established policies prohibiting access.
Connection Limits
An FTP site may have a limited quantity of available simultaneous connections. If this number is met, further connection attempts will be denied and logged for administrative purposes.
Bandwidth Limit
A bandwidth limit governs how much information can be transferred at a time. If this number is close to being met, the connection will become slower. If the communication between the computer and server exceeds an established duration, the connections will time out, resulting in an error.
In Feburary 2016 17,
Friday, 12 February 2016
What Is an FTP Server?In Feburary 2016 12,
In Feburary 2016 12,
The first published standard for the File Transfer Protocol predates the Transmission Control Protocol and Internet Protocol (TCP/IP) in use today. Published in 1971, FTP ran over the Network Control Protocol (NCP), the Internet's predecessor. It was designed to facilitate indirect exchanges across the network--those exchanges in which data or programs were transmitted to a different system to be executed or worked on.
Uses
FTP was originally designed for large bulk transfers of data, so it's ideally suited for file downloads. This is particularly true across the Internet, where FTP is used commonly as the mechanism for downloading patches, songs and purchased programs.
Function
At a technical level, FTP uses an out-of-band control mechanism. This means the data moves between client and server using one communication path. Control messages that govern the flow of that data move between the systems on a different communication channel. Because FTP was designed for file transfers, it leverages the TCP as an underlying protocol, which includes more robust packet delivery assurance.
Identification
Much like most other client/server relationships, the FTP client is the system that makes a request for data, and the FTP server provides that data. It is a common Internet practice to reserve a specific machine or even a set (or 'farm') of machines to function as FTP servers for an enterprise. Their purpose is to listen for client requests and (assuming security checks allow for it) quickly and accurately transmit large files to those clients. If your web browser suddenly reads 'ftp://
' you'll know you're leveraging the FTP protocol in your download.
Benefits
Web pages, which commonly download through the HyperText Transfer Protocol (HTTP), are usually comprised of many small files that must be simultaneously downloaded to a wide variety of clients in small degrees. Any given web page may make dozens or even hundreds of information requests just to populate a single page. This is a fundamentally different style of work than one request that results in several dozen megabytes of continuous data download. It is precisely because of this difference that FTP servers have continued to have their place amid the many web servers on the Internet.
Design
Because FTP servers are designed for large file transfers, they are best used as a part of an overall Internet server strategy. It's common, for instance, to have general informational pages hosted by web (HTTP) servers and include links in these pages to separate servers used to host large files for download--such as music, videos, large PDF documents, computer code and patches. Because security can be an issue with FTP (originally designed to send usernames and passwords in clear text), it is typical to see FTP servers host files that do not require specific permission for download--or to use a federated security model that leaves authentication and authorization to other systems.
In Feburary 2016 12,
The first published standard for the File Transfer Protocol predates the Transmission Control Protocol and Internet Protocol (TCP/IP) in use today. Published in 1971, FTP ran over the Network Control Protocol (NCP), the Internet's predecessor. It was designed to facilitate indirect exchanges across the network--those exchanges in which data or programs were transmitted to a different system to be executed or worked on.
Uses
FTP was originally designed for large bulk transfers of data, so it's ideally suited for file downloads. This is particularly true across the Internet, where FTP is used commonly as the mechanism for downloading patches, songs and purchased programs.
Function
At a technical level, FTP uses an out-of-band control mechanism. This means the data moves between client and server using one communication path. Control messages that govern the flow of that data move between the systems on a different communication channel. Because FTP was designed for file transfers, it leverages the TCP as an underlying protocol, which includes more robust packet delivery assurance.
Identification
Much like most other client/server relationships, the FTP client is the system that makes a request for data, and the FTP server provides that data. It is a common Internet practice to reserve a specific machine or even a set (or 'farm') of machines to function as FTP servers for an enterprise. Their purpose is to listen for client requests and (assuming security checks allow for it) quickly and accurately transmit large files to those clients. If your web browser suddenly reads 'ftp://
' you'll know you're leveraging the FTP protocol in your download.
Benefits
Web pages, which commonly download through the HyperText Transfer Protocol (HTTP), are usually comprised of many small files that must be simultaneously downloaded to a wide variety of clients in small degrees. Any given web page may make dozens or even hundreds of information requests just to populate a single page. This is a fundamentally different style of work than one request that results in several dozen megabytes of continuous data download. It is precisely because of this difference that FTP servers have continued to have their place amid the many web servers on the Internet.
Design
Because FTP servers are designed for large file transfers, they are best used as a part of an overall Internet server strategy. It's common, for instance, to have general informational pages hosted by web (HTTP) servers and include links in these pages to separate servers used to host large files for download--such as music, videos, large PDF documents, computer code and patches. Because security can be an issue with FTP (originally designed to send usernames and passwords in clear text), it is typical to see FTP servers host files that do not require specific permission for download--or to use a federated security model that leaves authentication and authorization to other systems.
In Feburary 2016 12,
Monday, 8 February 2016
How to Set Up a Proxy ServerIn Feburary 2016 08,
In Feburary 2016 08,
Set up WinProxy. WinProxy is widely used for windows-based servers which also provides Network Address Translation (NAT) and also supports HTTP, Real Audio, Real Video, FTP, Telnet, Secure Sockets and DNS. The system is popularity because it doesn't need to have any software loaded on the client's end, thereby saving time and effort.
Ensure that all the systems, including the client's systems, have been configured with TCP/IP (Transmission Control Protocol/Internet Protocol). TCP/IP is the basic communication language or protocol used by Internet, as well as private networks, to access the intranet (internal sites) or extranet (external sites).
Run the installation wizard for the WinProxy. You would need to initially enter the product key on the initial screen to register the product.
Select the type of Internet connection and choose the name of your connection.
Enter the user name and password of your Internet connection.
Let the automactic configuration scripts of the WinProxy run. This allows WinProxy to assign IP (Internet Protocol) addresses automatically to each device within the LAN (Local Area Network), meaning the internal connections. Each IP is unique on each device.
Follow the prompt to disconnect from your network, if you are already connected. WinProxy will then go through the verifications of each operation.
Verify if your proxy server works by having a tester or client computer test the system. The person should be allowed to get through the selected sites. Also, the proxy server should be able to check the URL (Uniform Resource Locator) of outgoing requests made for Web pages. This is done by inspecting HTTP GET and POST messages. Lastly, the system should also be able to see incoming data traffic, including filtering content of incoming messages.
In Feburary 2016 08,
Set up WinProxy. WinProxy is widely used for windows-based servers which also provides Network Address Translation (NAT) and also supports HTTP, Real Audio, Real Video, FTP, Telnet, Secure Sockets and DNS. The system is popularity because it doesn't need to have any software loaded on the client's end, thereby saving time and effort.
Ensure that all the systems, including the client's systems, have been configured with TCP/IP (Transmission Control Protocol/Internet Protocol). TCP/IP is the basic communication language or protocol used by Internet, as well as private networks, to access the intranet (internal sites) or extranet (external sites).
Run the installation wizard for the WinProxy. You would need to initially enter the product key on the initial screen to register the product.
Select the type of Internet connection and choose the name of your connection.
Enter the user name and password of your Internet connection.
Let the automactic configuration scripts of the WinProxy run. This allows WinProxy to assign IP (Internet Protocol) addresses automatically to each device within the LAN (Local Area Network), meaning the internal connections. Each IP is unique on each device.
Follow the prompt to disconnect from your network, if you are already connected. WinProxy will then go through the verifications of each operation.
Verify if your proxy server works by having a tester or client computer test the system. The person should be allowed to get through the selected sites. Also, the proxy server should be able to check the URL (Uniform Resource Locator) of outgoing requests made for Web pages. This is done by inspecting HTTP GET and POST messages. Lastly, the system should also be able to see incoming data traffic, including filtering content of incoming messages.
In Feburary 2016 08,
Subscribe to:
Comments (Atom)