Abstract: Various exemplary embodiments relate to a method of preventing extreme coresidency hazards among application instances in a cloud network. The method includes determining a first failure group of a first instance of an application; establishing a connection with a second instance of a peer application; determining a second failure group of the second instance; comparing the first failure group to the second failure group; and establishing a second connection with a third instance of the peer application if the first failure group and the second failure group share a failure point.

Abstract: A system, method, apparatus and mechanism for estimating worst-case time complexity of a regular expression defining a pattern adapted for identifying malicious packets and comprising one or more back-references (backref-regex) by constructing a non-deterministic finite automaton (NFA) corresponding to the backref-regex (backref-NFA), wherein the backref-NFA comprises a plurality of NFA-states and a respectively labeled edge for each of the one or more back-references of the backref-regex; performing liveness analysis on the backref-NFA to determine for each NFA-state of the backref-NFA a set of back-references alive at the NFA-state; and determining a maximum number of alive back-references over the plurality of NFA-states, wherein the determined maximum number is indicative of the worst-case time complexity of the backref-regex.

Abstract: Various exemplary embodiments relate to a method of preventing extreme coresidency hazards among application instances in a cloud network. The method includes determining a first failure group of a first instance of an application; establishing a connection with a second instance of a peer application; determining a second failure group of the second instance; comparing the first failure group to the second failure group; and establishing a second connection with a third instance of the peer application if the first failure group and the second failure group share a failure point.

Abstract: Various exemplary embodiments relate to a method of preventing extreme coresidency hazards among application instances in a cloud network. The method includes determining a first failure group of a first instance of an application; establishing a connection with a second instance of a peer application; determining a second failure group of the second instance; comparing the first failure group to the second failure group; and establishing a second connection with a third instance of the peer application if the first failure group and the second failure group share a failure point.

Abstract: Various exemplary embodiments relate to a method of preventing extreme coresidency hazards among application instances in a cloud network. The method includes determining a first failure group of a first instance of an application; establishing a connection with a second instance of a peer application; determining a second failure group of the second instance; comparing the first failure group to the second failure group; and establishing a second connection with a third instance of the peer application if the first failure group and the second failure group share a failure point.

Abstract: Methods and apparatus are provided for incremental analysis of one or more properties of a program. According to one aspect of the invention, at least one property of a software program is evaluated, given one or more changes to the software program. Nodes in a derivation graph are identified corresponding to changed edges in a control flow graph representation of the software program, wherein the derivation graph describes an earlier evaluation of the software program. In addition, at least one of the identified nodes in the derivation graph is updated and the derivation graph is traversed outward from a location of a change. The revised derivation graph can optionally be further processed to remove false errors.

Abstract: A system, method, apparatus and mechanism for estimating worst-case time complexity of a regular expression defining a pattern adapted for identifying malicious packets and comprising one or more back-references (backref-regex) by constructing a non-deterministic finite automaton (NFA) corresponding to the backref-regex (backref-NFA), wherein the backref-NFA comprises a plurality of NFA-states and a respectively labeled edge for each of the one or more back-references of the backref-regex; performing liveness analysis on the backref-NFA to determine for each NFA-state of the backref-NFA a set of back-references alive at the NFA-state; and determining a maximum number of alive back-references over the plurality of NFA-states, wherein the determined maximum number is indicative of the worst-case time complexity of the backref-regex.

Abstract: A packet is compared to a pattern defined by a regular expression with back-references (backref-regex) in a single pass of a non-deterministic finite automaton corresponding to the backref-regex (backref-NFA) that includes representations for all backref-regex's back-references. The packet's characters are sequentially selected and analyzed against the backref-NFA until a match or no-match between the packet and pattern is determined. Upon selecting a character, a corresponding configurations-set is updated, where the set includes configurations associated with respective NFA-states of the backref-NFA and indicating whether the selected character is being matched against a back-reference. With the configurations-set being updated the comparison process proceeds along backref-NFA's NFA-states. The updated configurations-set includes configurations associated with NFA-states reachable from the configurations in the pre-updated set. When the configurations-set includes a final state, a match is determined.

Abstract: Access by multiple threads to a common resource can be controlled using a bias-lock having a single owner thread selected from among the plurality of threads. The bias-lock includes an n-process lock for which non-owner processes compete and a 2-process lock for which the owner and non-owner holder of the n-process lock compete. The owner of the bias-lock can be switched to one of the non-owner threads without suspending the owner thread. An asymmetric lock can be used to eliminate the need for the 2-process lock. Bias-locks can further be extended to provide read/write bias locking mechanisms.

Abstract: A packet is compared to a pattern defined by a regular expression with back-references (backref-regex) in a single pass of a non-deterministic finite automaton corresponding to the backref-regex (backref-NFA) that includes representations for all backref-regex's back-references. The packet's characters are sequentially selected and analyzed against the backref-NFA until a match or no-match between the packet and pattern is determined. Upon selecting a character, a corresponding configurations-set is updated, where the set includes configurations associated with respective NFA-states of the backref-NFA and indicating whether the selected character is being matched against a back-reference. With the configurations-set being updated the comparison process proceeds along backref-NFA's NFA-states. The updated configurations-set includes configurations associated with NFA-states reachable from the configurations in the pre-updated set. When the configurations-set includes a final state, a match is determined.