8redhat.com Technology overview What’s new in Red Hat Enterprise Linux 7
achieving clock accuracy in the sub-microsecond range, which is far more accurate than is
typically obtainable with the network time protocol (NTP). This feature is particularly important
for applications in the nancial services and trading-related industries, where application latency
is measured in microseconds.
TEAM DRIVER LINK AGGREGATION
The Team Driver project is new for Red Hat Enterprise 7 beta and provides a mechanism to team
multiple network devices (ports) into a single logical interface at the data link layer (layer 2). This
mechanism is typically used to increase the maximum bandwidth and provide redundancy.
Team Driver identies only the necessary data fast-path parts in the kernel, and the majority of its
logic is implemented as a user space daemon. This approach provides advantages over traditional
bonding such as more stability, easier debugging, and simpler extensions while providing equal or
better performance.
TCP ENHANCEMENTS
Various improvements to transmission control protocol (TCP) aim to reduce latency for
connection-oriented services such as web servers built on Red Hat Enterprise Linux.
•Fast Open is an experimental TCP extension (not yet approved by the Internet Assigned
Numbers Authority (IANA)) designed to reduce the overhead when establishing a TCP connection
by eliminating one round time trip (RTT) from certain kinds of TCP conversations. Fast Open could
result in speed increases of between 4% and 41% in page-load times.
•Tail loss probe (TLP), an experimental algorithm, improves the efciency of how the TCP
networking stack deals with lost packets at the end of a TCP transaction. TLP could reduce
re-transmission timeouts by 15% and shorten HTTP response times by an average of 6%.
•Early Retransmit (RFC 5827) allows the transport to use fast retransmits to recover segment
losses that would otherwise require a lengthy timeout. Connections can recover from lost
packets faster, which decreases overall latency.
•Proportional Rate Reduction (PRP) is an experimental algorithm designed to return to the
maximum transfer rate quickly. It can potentially reduce HTTP response times by 3-10%.
40G ETHERNET LINK SPEED
Red Hat Enterprise Linux 7 beta supports 40G Ethernet link speeds, which enables faster network
communication for systems and applications.
LOW-LATENCY SOCKETS
Low-latency sockets are a software implementation that reduces networking latency and jitter
within the kernel. This implementation makes it easy for applications to poll for new packets directly
in the network driver which speeds up packets moving into the network stack. Applications that are
sensitive to unpredictable latency benet from the top-down, busy-wait polling method that replaces
interrupts for incoming packets.
Manymanuals.com
Manymanuals.de
Manymanuals.fr
Manymanuals.it
Manymanuals.pl
Manymanuals.cz
Manymanuals.es
Manymanuals-pt.com
Commenti su questo manuale