Steve White

Linux sockets in TIME_WAIT status

About Linux sockets in TIME_WAIT status

We recently came across an application used a significant number of open/close TCP connections under Redhat Enterprise Linux 5.4. As a result the system ran out of local ports to open new connections due a number of sockets that were stuck in TIME_WAIT status. Using the ‘netstat’ command from a shell we could see that it was this particular application causing the problem because the destination port numbers were all the same.

Sockets which are listed in CLOSE_WAIT status are different and many of these usually means that a particular application isn’t closing it’s socket file descriptors off correctly.

More about fixing Linux socket TIME_WAIT status

This problem was causing issues for all network related software on the system. To alleviate this problem we set the following kernel parameters as root and rebooted:

echo 1 > /proc/sys/net/ipv4/tcp_tw_recycle
echo 1 > /proc/sys/net/ipv4/tcp_tw_reuse
echo 30 > /proc/sys/net/ipv4/tcp_fin_timeout

After this change the number of sockets in TIME_WAIT state were drastically reduced, problem solved!

Regards,

Steve

CEO

What is Real Time Intelligence ?

Real-time Intelligence (RTI) is the process of delivering information about your data as it happens. The speed of today’s processing systems has moved classical data warehousing into the realm of real-time. In this context, real-time means a range from milliseconds to a few seconds after the event has occurred. While traditional business intelligence presents historical data for manual analysis, real-time intelligence compares current data with historical patterns to detect problems or opportunities automatically.

  • Business transactions can be fed to the NetNow service as they occur to maintain the current state of the enterprise.
  • Real-time intelligence not only supports the ability to derive information and knowledge from past enterprise activity, but it also provides real-time tactical support.
  • Drive enterprise actions and react immediately to events as they occur.
  • Automated analysis capability enables corrective actions to be initiated and/or business rules to be adjusted to optimize business processes.

NetNow creates a “single source of truth” from all your data sources and gives you the power to easily create new ways to see your data, just the way you need to. Knowledge is Power and NetNow brings intel to your fingertips.
Download the info-graphic

Integrations

Twitter Integration

nnApp for Twitter integration

Type: bi-directional

Supported Platforms: twitter.com

Version 1.0

Twitter Integration – Integrates via twitter API to monitor twitter data. Access the direct download here : Coming 2013

About Apps for data integration

Integrations are NetNow Apps that allow you to easily integrate your data and connect existing applications or systems the NetNow service. Integrations are available to many different platforms and applications whether they are based in the cloud or on your premises. Using integrations you can quickly and easily extend an existing application to bring it to the cloud or develop entirely new solutions.

Colin Rutland

Visualizing hierarchical data with the hyperbolic tree widget

About hyperbolic tree

In a previous post I explained how the Bullet Graph and Sparkline widgets can help dashboard designers use valuable screen real-estate more economically. These charts are ideal for displaying single values and simple sequences of values. But a different set of problems arises when hierarchical data needs to be displayed, as users need to visualize not just the information relating to each individual node, but also the existence (and possibly the nature) of the relationships between nodes.

NetNow provides a wide range of widgets for displaying hierarchical data including trees, tree grids (such as the service summary) and multi-level pie charts. All of these are useful visualizations, but can become cluttered with very large trees.

A Hyperbolic Tree (or “Hypertree”) overcomes this limitation by reducing the screen space used to display nodes exponentially as the distance from the centre of the chart increases. This means that a Hypertree can pack much more information into the same amount of space than a standard tree graph:

The NetNow Hypertree widget enables easy navigation of very large hierarchies of nodes. Clicking on any node brings it immediately to the centre of the chart, automatically reducing the scale of surrounding nodes that are not the user’s current focus of attention.

The use of hyperbolic trees as a browsing mechanism for large hierarchies of data was pioneered by John Lamping, Ramana Rao and Peter Pirolli and is described in more detail in their original paper.

Integrations

Tivoli Enterprise Console event integration (TEC/TEP)

nnApp for Tivoli Enterprise event integration (TEC/TEP)

Type: bi-directional

Supported Version: TBA

Version 1.0

Tivoli Enterprise Console event integration – Platform & full functional details to follow. Access the direct download here : Coming 2013

About Apps for data integration

Integrations are NetNow Apps that allow you to easily integrate your data and connect existing applications or systems the NetNow service. Integrations are available to many different platforms and applications whether they are based in the cloud or on your premises. Using integrations you can quickly and easily extend an existing application to bring it to the cloud or develop entirely new solutions.

 

Integrations

Oracle Enterprise Manager Integration

nnApp for Oracle Enterprise Manager integration

Type: bi-directional

Supported Version: TBA

Version 1.0

Oracle Enterprise Manager Integration  • Platform & full functional details to follow. Access the direct download here : Coming 2013

About Apps for data integration

Integrations are NetNow Apps that allow you to easily integrate your data and connect existing applications or systems the NetNow service. Integrations are available to many different platforms and applications whether they are based in the cloud or on your premises. Using integrations you can quickly and easily extend an existing application to bring it to the cloud or develop entirely new solutions.

Integrations

NetIQ AppManager Integration

nnApp for NetIQ AppManager integration

Type: bi-directional

Supported Version: TBA

Version 1.0

NetIQ AppManager Integration Manager • Platform & full functional details to follow. Access the direct download here : Coming 2013

About Apps for data integration

Integrations are NetNow Apps that allow you to easily integrate your data and connect existing applications or systems the NetNow service. Integrations are available to many different platforms and applications whether they are based in the cloud or on your premises. Using integrations you can quickly and easily extend an existing application to bring it to the cloud or develop entirely new solutions.

Integrations

Nagios integration

nnApp for Nagios integration

Type: uni-directional

Supported Version: TBA

Version 1.0

Nagios integration  • Platform & full functional details to follow. Access the direct download here : Coming 2013

About Apps for data integration

Integrations are NetNow Apps that allow you to easily integrate your data and connect existing applications or systems the NetNow service. Integrations are available to many different platforms and applications whether they are based in the cloud or on your premises. Using integrations you can quickly and easily extend an existing application to bring it to the cloud or develop entirely new solutions.

Integrations

MS Systems Center Operations Manager SCOM integration

nnApp for MS SCOM integration

Type: bi-directional

Supported Version: TBA

Version 1.0

MS Systems Center Operations Manager SCOM integration • Platform & full functional details to follow. Access the direct download here : Coming 2013

About Apps for data integration

Integrations are NetNow Apps that allow you to easily integrate your data and connect existing applications or systems the NetNow service. Integrations are available to many different platforms and applications whether they are based in the cloud or on your premises. Using integrations you can quickly and easily extend an existing application to bring it to the cloud or develop entirely new solutions.

Integrations

MS Operations Manager (MOM)

nnApp for MS Operations Manager (MOM)

Type: bi-directional

Supported Version: TBA

Version 1.0

MS Operations Manager (MOM) • Platform & full functional details to follow. Access the direct download here : Coming 2013

About Apps for data integration

Integrations are NetNow Apps that allow you to easily integrate your data and connect existing applications or systems the NetNow service. Integrations are available to many different platforms and applications whether they are based in the cloud or on your premises. Using integrations you can quickly and easily extend an existing application to bring it to the cloud or develop entirely new solutions.