Abstract: Embodiments of the present invention provide a method, system and computer program product for multi-scale network traffic generation. In one embodiment of the invention, a network traffic generation method can be provided. The method can include defining multiple, different scales in an n-state MMPP model to accommodate a full characteristic response of a modeled traffic scenario. The method further can include establishing a transition window for each of the scales and determining a state through the transition window for selected ones of the scales. Finally, the method can include computing an inter-packet time according to the determined state for each of the selected ones of the scales and generating and transmitting packets for the selected ones of the scales utilizing a correspondingly computed inter-packet time.

Abstract: A design structure embodied in a machine readable storage medium for at least one of designing, manufacturing, and testing a design is provided. The design structure includes a network traffic generation system. The system can include a Markov modified Poisson process (MMPP) model, a packet scheduler coupled to the MMP model, a data store of transition windows defined for different defined scales, traffic generation parameter computing logic comprising program code enabled to compute traffic generation parameters for different scales according to respective states identified within different transition windows in the data store for the different scales, and a packet transmitter coupled to the packet scheduler.

Abstract: Methods and products are disclosed for analyzing network traffic using an improved Markov Modulated Poisson Process Model with one bursty state and a plurality of idle states that include: establishing a time scale of operation for each state in the improved MMPP model; establishing a transition value for each state in dependence upon the time scale of operation for the state; measuring inter-arrival times between individual packets received in one or more network adapters; and determining a current state for the network traffic independence upon the measured inter-arrival time of a most recently received packet and the transition values.

Abstract: Data communication in network traffic is modeled in real time and is analyzed using a 2-state Markov modified Poissen process (MMPP). The traffic inter-arrival times for bursty and idle states define a transition window [?1max, ?2min] represented by the boundary values ?1max for the inter-arrival time for bursty traffic, and ?2min for the inter-arrival time for idle traffic. Changes in the values of ?1max and ?2min are tracked over time, and the size of the transition window is enlarged or decreased based upon relative changes in these values. If the inter-rival times for the bursty state and the idle state become approximately equal, the model defaults to a single state model. The modeling is applicable to the synchronization of polling and blocking in a low-latency network system. This permits the adoptive selection of poll or block to maximize CPU utilization and interrupt latency.

Abstract: Aspects of the invention provide an improved solution for processing packets in a packetized communications network. For example, a next packet in a set of incoming packets placed in a plurality of queues is selected by obtaining a random/pseudo-random search key and identifying one of the plurality of queues based on the search key and a Patricia tree that includes at least one child node for each of the plurality of queues. A greedy algorithm can be used to select an alternative queue should the first selected queue be empty.

Abstract: Methods, apparatus, and products are disclosed for analyzing network traffic using an improved Markov Modulated Poisson Process Model with two barrier states that include: retrieving a previous state for the network traffic; measuring inter-arrival times between individual packets received in one or more network adapters; establishing a transition window in dependence upon the measured inter-arrival times, the transition window having a transition value ?Bmax that represents an upper boundary for the inter-arrival times in a bursty state and having a transition value ?Imin that represents a lower boundary for the inter-arrival times in an idle state; retrieving a previous fence value that prevents premature transitions into the idle state or the bursty state; and determining a current state for the network traffic in dependence upon the previous state for the network traffic, an inter-arrival time of a most recently received packet, the transition values, and the previous fence value.

Abstract: A design structure embodied in a machine readable storage medium for at least one of designing, manufacturing, and testing a design is provided. The design structure includes a network traffic generation system. The system can include a Markov modified Poisson process (MMPP) model, a packet scheduler coupled to the MMP model, a data store of transition windows defined for different defined scales, traffic generation parameter computing logic comprising program code enabled to compute traffic generation parameters for different scales according to respective states identified within different transition windows in the data store for the different scales, and a packet transmitter coupled to the packet scheduler.

Abstract: Aspects of the invention provide an improved solution for processing packets in a packetized communications network. For example, a next packet in a set of incoming packets placed in a plurality of queues is selected by obtaining a random/pseudo-random search key and identifying one of the plurality of queues based on the search key and a Patricia tree that includes at least one child node for each of the plurality of queues. A greedy algorithm can be used to select an alternative queue should the first selected queue be empty.

Abstract: Methods, apparatus, and products are disclosed for analyzing network traffic using an improved Markov Modulated Poisson Process Model with two barrier states that include: retrieving a previous state for the network traffic; measuring inter-arrival times between individual packets received in one or more network adapters; establishing a transition window in dependence upon the measured inter-arrival times, the transition window having a transition value ?Bmax that represents an upper boundary for the inter-arrival times in a bursty state and having a transition value ?Imin that represents a lower boundary for the inter-arrival times in an idle state; retrieving a previous fence value that prevents premature transitions into the idle state or the bursty state; and determining a current state for the network traffic in dependence upon the previous state for the network traffic, an inter-arrival time of a most recently received packet, the transition values, and the previous fence value.

Abstract: Embodiments of the present invention address deficiencies of the art in respect to TCP processing and provide a novel and non-obvious method, system and computer program product for selectively accelerating TCP connections. In one embodiment of the invention, a method of selectively accelerating TCP connections in TCP/IP based inter-process communications can be provided. The method can include establishing a TCP connection for TCP/IP inter-process communications, observing a block size for the TCP connection, and switching between TCP/IP processing in a host processor and TCP/IP processing in a TOE in a network adapter coupled to the host processor based upon the observed block size exceeding a threshold value.

Abstract: The invention is directed to the identifying, tracking, and storing of hot cache lines in an SMP environment. A method in accordance with an embodiment of the present invention includes: accessing, by a first processor, a cache line from main memory; modifying and storing the cache line in the L2 cache of the first processor; requesting, by a second processor, the cache line; identifying, by the first processor, that the cache line stored in the L2 cache of the first processor has previously been modified; marking, by the first processor, the cache line as a hot cache line; forwarding the hot cache line to the second processor; modifying, by the second processor, the hot cache line; and storing the hot cache line in the hot cache of the second processor.

Abstract: Methods and products are disclosed for analyzing network traffic using an improved Markov Modulated Poisson Process Model with one bursty state and a plurality of idle states that include: establishing a time scale of operation for each state in the improved MMPP model; establishing a transition value for each state in dependence upon the time scale of operation for the state; measuring inter-arrival times between individual packets received in one or more network adapters; and determining a current state for the network traffic independence upon the measured inter-arrival time of a most recently received packet and the transition values.

Abstract: Embodiments of the present invention provide a method, system and computer program product for multi-scale network traffic generation. In one embodiment of the invention, a network traffic generation method can be provided. The method can include defining multiple, different scales in an n-state MMPP model to accommodate a full characteristic response of a modeled traffic scenario. The method further can include establishing a transition window for each of the scales and determining a state through the transition window for selected ones of the scales. Finally, the method can include computing an inter-packet time according to the determined state for each of the selected ones of the scales and generating and transmitting packets for the selected ones of the scales utilizing a correspondingly computed inter-packet time.

Abstract: Data communication in network traffic is modeled in real time and is analyzed using a 2-state Markov modified Poissen process (MMPP). The traffic inter-arrival times for bursty and idle states define a transition window [?1max, ?2min] represented by the boundary values ?1max for the inter-arrival time for bursty traffic, and ?2min for the inter-arrival time for idle traffic. Changes in the values of ?1max and ?2min are tracked over time, and the size of the transition window is enlarged or decreased based upon relative changes in these values. If the inter-rival times for the bursty state and the idle state become approximately equal, the model defaults to a single state model. The modeling is applicable to the synchronization of polling and blocking in a low-latency network system. This permits the adoptive selection of poll or block to maximize CPU utilization and interrupt latency.

Abstract: Self-similar data communication in network traffic is modeled real time and is analyzed using a Markov modified Poissen process (MMPP) to characterize the traffic flow and to accommodate high variability in traffic flow from one time period to the other. The analysis is performed at multiple time levels using a bottom-up approach. The parameters of the model are adjustable at each level according to the traffic parameters at that level. Each model consists of 2 states of network traffic behavior comprising a bursty state representing heavy traffic conditions and an idle state representing light traffic conditions. A transition window defines the upper time interval for the receipt of packets in the bursty state and the lower time interval for the receipt of packets in the idle state. If the inter-rival times for the bursty state and the idle state become approximately equal, the model defaults to a single state model.

Abstract: Data communication in network traffic is modeled in real time and is analyzed using a 2-state Markov modified Poissen process (MMPP). The traffic inter-arrival times for bursty and idle states define a transition window [&lgr;1max, &lgr;2min] represented by the boundary values &lgr;1max for the inter-arrival time for bursty traffic, and &lgr;2min for the inter-arrival time for idle traffic. Changes in the values of &lgr;1max and &lgr;2min are tracked over time, and the size of the transition window is enlarged or decreased based upon relative changes in these values. If the inter-rival times for the bursty state and the idle state become approximately equal, the model defaults to a single state model. The modeling is applicable to the synchronization of polling and blocking in a low-latency network system. This permits the adoptive selection of poll or block to maximize CPU utilization and interrupt latency.

Abstract: Self-similar data communication in network traffic is modeled real time and is analyzed using a Markov modified Poissen process (MMPP) to characterize the traffic flow and to accommodate high variability in traffic flow from one time period to the other. The analysis is performed at multiple time levels using a bottom-up approach. The parameters of the model are adjustable at each level according to the traffic parameters at that level. Each model consists of 2 states of network traffic behavior comprising a bursty state representing heavy traffic conditions and an idle state representing light traffic conditions. A transition window defines the upper time interval for the receipt of packets in the bursty state and the lower time interval for the receipt of packets in the idle state. If the inter-rival times for the bursty state and the idle state become approximately equal, the model defaults to a single state model.

Abstract: A system, computer program product and method for reallocating memory space for storing a partitioned cache. A server may be configured to receive requests to access a particular logical drive. One or more logical drives may be coupled to an adapter. A plurality of adapters may be coupled to the server. Each logical drive may be associated with one or more stacks where each stack may comprise one or more cache entries for storing information. The one or more stacks associated with a logical drive may be logically grouped into a logically grouped stack associated with that logical drive. Each of the logically grouped stacks of the one or more logical drives coupled to an adapter may be logically grouped into a logically grouped stack associated with that adapter. By logically grouping stacks, memory supporting a partitioned cache may adaptively be reallocated in response to multiple criteria thereby improving the performance of the cache.

Abstract: A system, computer program product and method for designing a cache. A server in a network system, e.g., file system, database system, may receive requests forming a workload. A trace may be performed on the workload to provide information such as the frequency count for each Logical Block Address (LBA) requested in the workload. The trace may then be analyzed by grouping the LBA's with the same frequency count and determining the number of groups counted in the trace. Upon analyzing the trace, an LRU-LFU cache may be designed. An LRU-LFU cache may comprise one or more stacks of cache entries where the number of stacks corresponds to the number of frequency groups counted in the trace. Each particular stack may then have a length based on the number of logical addresses with the same frequency count associated with that particular stack.

Abstract: A system, computer program product and method for reconfiguring a cache. A cache array may be created with one or more stacks of cache entries based on a workload. The one or more stacks may be ordered from most frequently used to least frequently used. The cache entries in each particular stack may be ordered from most recently used to least recently used. When a cache hit occurs, the cache entry requested may be stored in the next higher level stack if the updated frequency count is associated with the next higher level stack. When a cache miss occurs, the cache entry in a least recently used stack position in the stack with the lowest number of cache hits in the one or more stack positions tracked during a particular period of time may be evicted thereby allowing the requested information to be stored in the lowest level stack.