bdp s470

packets. 1000 2000 /proc/sys/net/core/somaxconn Defines the length of the maximum listening queue for each port in the system, which is a global parameter. 128 2048 /proc/sys/net/core/optmem_max Represents the size of the maximum buffer allowed for each socket. 20480 81920 /proc/sys/net/ipv4/tcp_mem Determine how the TCP stack should reflect memory usage, and each value is in a memory page (usually 4KB). The

sliding window can only reach the read cache of 3/4.3.net.ipv4.tcp_rmem4096 87380 6291456The first is to accept the minimum byte of the bufferThe second is to accept the initial value of the buffer length used to initialize the sock sk_rcvbuf, replacing the Rmem_defaultThe third one is to accept the maximum buffer length to adjust the sk_rcvbuf of the sock4.net.core.rmem_defaultDefault Accept Window size (bytes) for all protocolsAcceptable window (Rwnd) reasonable value depends on

invalid connections.NET.IPV4.TCP_KEEPALIVE_INTVL = 30When the probe message is not responding, the time interval (in seconds) for the message to be re-sent.Net.ipv4.tcp_keepalive_probes = 3How many TCP keepalive probe packets are sent before the connection is determined to fail. The default value is 9. This value, multiplied by TCP_KEEPALIVE_INTVL, determines how much time a connection can have without a response after sending a keepalive.Net.ipv4.tcp_mem = 786432 1048576 1572864Determine how t

, messages can be discarded, thereby reducing the use of memory. For larger BDP You can increase these values (but remember that their units are memory pages, not bytes).Net.ipv4.tcp_rmem#与 Tcp_wmem is similar, but it represents the value of the receive buffer used for automatic tuning.Net.ipv4.tcp_wmem = 30000000 30000000 30000000#为自动调优定义每个 the memory used by the socket.The minimum number of bytes allocated #第一个值是为 the send buffer for the socket.#第二个

Active Queue Management(AQM) scheme is employed. Given an ambiguity in the choice of the AQM parametersAQM is rarely used in practice. On the other hand, in the basic Drop Tail routers, the buffer sizeIs the only one parameter to tune apart of the router capacity.The first proposed rule of thumb for the choice of the router buffer size is to choose the bufferSize equal to the Bandwidth-delay Product (BDP) of the outgoing link.It is observed that the

Upgrade BDP to PDC due to original PDC failure The Netdom tool is required for upgrading the PDC NETDOM is a system support tool to be installed prior to use (CD:/support/tools/suptools. MSI) Note: Must use the Administrator account to login to the BDC, even if the other administrator account does not work, because to seize schema master This step will be an error, no permissions First execute the "netdom query FSMO" command to see what the curren

ways to connect a database to a Java program: OCI mode, thin mode, and Jdbcodbc bridge mode:OCI mode:Application---JDBC API---driver---data sourceThin Way:Thin mode is pure Java implementation of TCP/IP communication, and OCI mode, the client through the native Java method call C library access to the server, and this C library is the OCI (Oracle called Interface), So this oci always needs to be installed with the Oracle clientJDBCODBC Bridge mode (for Windows platforms):Application--->JDBC API

: [SQL] DEFAULT_SDU_SIZE = 32767 in tnsnames. [SQL] sales.us.acme.com = (DESCRIPTION = (SDU = 32767) (ADDRESS = (PROTOCOL = tcp) (HOST = sales-server) (PORT = 1521) (CONNECT_DATA = (SERVICE_NAME = sales.us.acme.com) in listener. in the ora file, perform the following configuration: [SQL] SID_LIST_listener_name = (SID_LIST = (SID_DESC = (SDU = 32767) (SID_NAME = sales ). Configure the same row, so as not to adjust the same configuration after changing the role (3) Reasonably set the TCP Sockte Bu

well we can use it. If you must use Python to achieve, then basically preferred ipython+matplotlib, because here also need maps, estimated basemap. Matplotlib, install it later also to install one of its extended application basemap,100 more than M. Official documents / http matplotlib.org/basemap/ users/geography.html 。 As follows Map Sinks http://www. dituhui.com/ Arcgis, of course, this tool is more professional, not easy to learn. But this is a necessary tool for geographic informatio

Python crawler Baidu API call method and python crawler api call Call Baidu API to obtain latitude and longitude information. Import requestsimport jsonaddress = input ('enter location: ') par = {'address': address, 'key': 'cb649a25c1f81c1451adbeca73623251'} url = 'HTTP: // restapi.amap.com/v3/geocode/geo'res = requests. get (url, par) json_data = json. loads (res. text) geo = json_data ['geocodes '] [0] ['location'] longpolling = geo. split (',') [0] latitude = geo. split (',') [1] print (lon

preferred choice. Because map is also required here, it is estimated that Basemap is indispensable. Matplotlib. After installation, you need to install an extended application basemap, which is more than 100 MB. Official Document http://matplotlib.org/basemap/users/geography.html . As follows: Map http://www.dituhui.com/ Arcgis, of course, this tool is relatively professional and it is not easy to learn. But this is a necessary tool for geographic information, data visualization function is ve

value is a memory page (usually 4 kb ). The first value is the lower limit of memory usage. The second value is the maximum application pressure on the buffer zone in memory pressure mode. The third value is the upper limit of memory. At this level, messages can be discarded to reduce memory usage. For larger BDP values, you can increase these values (but remember that the unit is the memory page, not the byte ). Echo 0>/proc/sys/net/ipv4/tcp_timest

"); Imagewbmp (imagecreatefromwbmp ($ match [2]); } Else {} ?> Snoopy. class. php is a php class used to imitate the functions of a web browser. it can complete the tasks of obtaining webpage content and sending forms. Search and download this file by yourself. The above file requires a space that supports PHP. Baidu online storage uploads images and publishes shares. after obtaining the share address, the consumer id = 29160 uk = 2855065916 parameter. Use http: // yo

restrictions Net. ipv4.ip _ local_port_range = 2000 65000 # Increase the maximum TCP buffer size Net. ipv4.tcp _ rmem = 4096 87380 8388608 Net. ipv4.tcp _ wmem = 4096 87380 8388608 # Added the limit for automatically adjusting TCP buffer in Linux. # Minimum, default, and maximum number of bytes available # The maximum value is no less than 4 MB. If you use a very high BDP path, you can set a higher value. # Tcp Window Net. core. rmem_max = 8388608 Ne

, in a non-BDP network environment, HSTCP uses the same A and B as the standard TCP to ensure the friendliness of the two. When the window is large (critical value lowwindow=38), new A and B are adopted to achieve high throughput requirements. You can see the RFC3649 documentation for details.4. WestwoodIn wireless networks, it is found that Tcpwestwood is an ideal algorithm based on a large number of researches, and its main idea is to make bandwidth

that the second type of caching is no longer the basis of the BDP, but BBR has the principle that it will persist in MAX-BW and Min-rtt, and allow other algorithms to grab the second class of caches, cao! The gentlemen's agreement of TCP lets those other algorithms find that the second type of cache fills up, slowing down to the point where the first type of cache is not enough to fill, and Bbr says, "This is what you gave me."To summarize, BBR does

A program has an unlimited number of bugs, one day can find 1, these bugs have two different keywords, a, B, respectively, according to the two keywords are divided into n and m species, to collect all classes (summon the dragon) of the desired daysDP[I][J] Indicates that I have collected the expected days of type A and J BDp[i][j]=i/n*j/s*dp[i][j]+pp= (n-i)/n*j/s*dp[i+1][j]+i/n* (s-j)/s*dp[i][j+1]+ (n-i)/n* (s-j)/s*dp[i+1][j+1]+1dp[i][j]=p*n*s/of mov

, the smaller the number of buffer connections, and the larger the buffer becomes.13.5Tuning Core buffer size (UDP)AdjustmentUDP BuffersizeA. Adjust the bdp/#connections buffer A in the/etc/sysctl.conf file.The Input/reader in Bytes receives the data net.core.rmem_default the default value Net.core.rmem_max the maximum value B.Output/write in Bytes sends data Net.core.wmem_default Net.core.wmem_max B. Reload/etc/sysctl.conf sysctl–p13.6 Tuning TCP buf

beginning, and if the acceleration is no, it will lose 25% of the data), But the pacing rate obtained with BBR measurement has a completely different meaning. Cubic pacing rate and congestion window is an identity relationship, behind the definition of bdp, and BBR is a "two-stage probe" in the meaning of the Inside....Actually also very good understanding ah, the rate is an instantaneous amount, and inflight is a rate of integration, as long as the

Topic Link: Click to open the linkTest instructionsGiven n points of the tree, dyed two colors, different colors can not be adjacent and to be as many nodes to dye. Find the number of possible staining nodes for color A and color B. (Copy from Figo)And at least one dianran a, at least one Dianran bDp[i][j]=1 indicates that I Dianran j a color is feasible =0 expression is not feasible.Import Java.io.bufferedreader;import Java.io.inputstreamreader;impor