Search Results

Search found 333 results on 14 pages for 'passive'.

Page 2/14 | < Previous Page | 1 2 3 4 5 6 7 8 9 10 11 12  | Next Page >

  • Passive and active sockets

    - by davsan
    Quoting from this socket tutorial: Sockets come in two primary flavors. An active socket is con­nect­ed to a remote active socket via an open data con­nec­tion... A passive socket is not con­nect­ed, but rather awaits an in­com­ing con­nec­tion, which will spawn a new active socket once a con­nec­tion is es­tab­lished ... Each port can have a single passive socket binded to it, await­ing in­com­ing con­nec­tions, and mul­ti­ple active sockets, each cor­re­spond­ing to an open con­nec­tion on the port. It's as if the factory worker is waiting for new mes­sages to arrive (he rep­re­sents the passive socket), and when one message arrives from a new sender, he ini­ti­ates a cor­re­spon­dence (a con­nec­tion) with them by del­e­gat­ing someone else (an active socket) to ac­tu­al­ly read the packet and respond back to the sender if nec­es­sary. This permits the factory worker to be free to receive new packets. ... Then the tutorial explains that, after a connection is established, the active socket continues receiving data until there are no remaining bytes, and then closes the connection. What I didn't understand is this: Suppose there's an incoming connection to the port, and the sender wants to send some little data every 20 minutes. If the active socket closes the connection when there are no remaining bytes, does the sender have to reconnect to the port every time it wants to send data? How do we persist a once established connection for a longer time? Can you tell me what I'm missing here? My second question is, who determines the limit of the concurrently working active sockets?

    Read the article

  • Determining Maximum Txpower a WiFi Card Supports?

    - by BigGenius
    I have a Atheros R9285 wifi card. How can i determine , what is max. Txpower it can support? biggenius@hackbook:~$ iwconfig lo no wireless extensions. wlan0 IEEE 802.11abgn ESSID:"Default" Mode:Managed Frequency:2.437 GHz Access Point: 00:08:5C:9D:4F:40 Bit Rate=2 Mb/s Tx-Power=35 dBm Retry long limit:7 RTS thr:off Fragment thr:off Power Management:on Link Quality=24/70 Signal level=-86 dBm Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0 Tx excessive retries:140 Invalid misc:247 Missed beacon:0 eth0 no wireless extensions. biggenius@hackbook:~$ iw phy0 info Wiphy phy0 Band 1: Capabilities: 0x11ce HT20/HT40 SM Power Save disabled RX HT40 SGI TX STBC RX STBC 1-stream Max AMSDU length: 3839 bytes DSSS/CCK HT40 Maximum RX AMPDU length 65535 bytes (exponent: 0x003) Minimum RX AMPDU time spacing: 8 usec (0x06) HT TX/RX MCS rate indexes supported: 0-7 Frequencies: * 2412 MHz [1] (35.0 dBm) * 2417 MHz [2] (35.0 dBm) * 2422 MHz [3] (35.0 dBm) * 2427 MHz [4] (35.0 dBm) * 2432 MHz [5] (35.0 dBm) * 2437 MHz [6] (35.0 dBm) * 2442 MHz [7] (35.0 dBm) * 2447 MHz [8] (35.0 dBm) * 2452 MHz [9] (35.0 dBm) * 2457 MHz [10] (35.0 dBm) * 2462 MHz [11] (35.0 dBm) * 2467 MHz [12] (35.0 dBm) * 2472 MHz [13] (35.0 dBm) * 2484 MHz [14] (35.0 dBm) Bitrates (non-HT): * 1.0 Mbps * 2.0 Mbps (short preamble supported) * 5.5 Mbps (short preamble supported) * 11.0 Mbps (short preamble supported) * 6.0 Mbps * 9.0 Mbps * 12.0 Mbps * 18.0 Mbps * 24.0 Mbps * 36.0 Mbps * 48.0 Mbps * 54.0 Mbps Band 2: Capabilities: 0x11ce HT20/HT40 SM Power Save disabled RX HT40 SGI TX STBC RX STBC 1-stream Max AMSDU length: 3839 bytes DSSS/CCK HT40 Maximum RX AMPDU length 65535 bytes (exponent: 0x003) Minimum RX AMPDU time spacing: 8 usec (0x06) HT TX/RX MCS rate indexes supported: 0-7 Frequencies: * 5180 MHz [36] (35.0 dBm) * 5200 MHz [40] (35.0 dBm) * 5220 MHz [44] (35.0 dBm) * 5240 MHz [48] (35.0 dBm) * 5260 MHz [52] (35.0 dBm) (passive scanning, no IBSS, radar detection) * 5280 MHz [56] (35.0 dBm) (passive scanning, no IBSS, radar detection) * 5300 MHz [60] (35.0 dBm) (passive scanning, no IBSS, radar detection) * 5320 MHz [64] (35.0 dBm) (passive scanning, no IBSS, radar detection) * 5500 MHz [100] (35.0 dBm) (passive scanning, no IBSS, radar detection) * 5520 MHz [104] (35.0 dBm) (passive scanning, no IBSS, radar detection) * 5540 MHz [108] (35.0 dBm) (passive scanning, no IBSS, radar detection) * 5560 MHz [112] (35.0 dBm) (passive scanning, no IBSS, radar detection) * 5580 MHz [116] (35.0 dBm) (passive scanning, no IBSS, radar detection) * 5600 MHz [120] (35.0 dBm) (passive scanning, no IBSS, radar detection) * 5620 MHz [124] (35.0 dBm) (passive scanning, no IBSS, radar detection) * 5640 MHz [128] (35.0 dBm) (passive scanning, no IBSS, radar detection) * 5660 MHz [132] (35.0 dBm) (passive scanning, no IBSS, radar detection) * 5680 MHz [136] (35.0 dBm) (passive scanning, no IBSS, radar detection) * 5700 MHz [140] (35.0 dBm) (passive scanning, no IBSS, radar detection) * 5745 MHz [149] (35.0 dBm) * 5765 MHz [153] (35.0 dBm) * 5785 MHz [157] (35.0 dBm) * 5805 MHz [161] (35.0 dBm) * 5825 MHz [165] (35.0 dBm) Bitrates (non-HT): * 6.0 Mbps * 9.0 Mbps * 12.0 Mbps * 18.0 Mbps * 24.0 Mbps * 36.0 Mbps * 48.0 Mbps * 54.0 Mbps max # scan SSIDs: 4 max scan IEs length: 2257 bytes Coverage class: 0 (up to 0m) Supported Ciphers: * WEP40 (00-0f-ac:1) * WEP104 (00-0f-ac:5) * TKIP (00-0f-ac:2) * CCMP (00-0f-ac:4) * CMAC (00-0f-ac:6) Available Antennas: TX 0x1 RX 0x3 Configured Antennas: TX 0x1 RX 0x3 Supported interface modes: * IBSS * managed * AP * AP/VLAN * WDS * monitor * mesh point * P2P-client * P2P-GO software interface modes (can always be added): * AP/VLAN * monitor valid interface combinations: * #{ managed, WDS, P2P-client } <= 2048, #{ AP, mesh point, P2P-GO } <= 8, total <= 2048, #channels <= 1 Supported commands: * new_interface * set_interface * new_key * new_beacon * new_station * new_mpath * set_mesh_params * set_bss * authenticate * associate * deauthenticate * disassociate * join_ibss * join_mesh * remain_on_channel * set_tx_bitrate_mask * action * frame_wait_cancel * set_wiphy_netns * set_channel * set_wds_peer * Unknown command (82) * Unknown command (81) * Unknown command (84) * Unknown command (87) * Unknown command (85) * testmode * connect * disconnect Supported TX frame types: * IBSS: 0x0000 0x0010 0x0020 0x0030 0x0040 0x0050 0x0060 0x0070 0x0080 0x0090 0x00a0 0x00b0 0x00c0 0x00d0 0x00e0 0x00f0 * managed: 0x0000 0x0010 0x0020 0x0030 0x0040 0x0050 0x0060 0x0070 0x0080 0x0090 0x00a0 0x00b0 0x00c0 0x00d0 0x00e0 0x00f0 * AP: 0x0000 0x0010 0x0020 0x0030 0x0040 0x0050 0x0060 0x0070 0x0080 0x0090 0x00a0 0x00b0 0x00c0 0x00d0 0x00e0 0x00f0 * AP/VLAN: 0x0000 0x0010 0x0020 0x0030 0x0040 0x0050 0x0060 0x0070 0x0080 0x0090 0x00a0 0x00b0 0x00c0 0x00d0 0x00e0 0x00f0 * mesh point: 0x0000 0x0010 0x0020 0x0030 0x0040 0x0050 0x0060 0x0070 0x0080 0x0090 0x00a0 0x00b0 0x00c0 0x00d0 0x00e0 0x00f0 * P2P-client: 0x0000 0x0010 0x0020 0x0030 0x0040 0x0050 0x0060 0x0070 0x0080 0x0090 0x00a0 0x00b0 0x00c0 0x00d0 0x00e0 0x00f0 * P2P-GO: 0x0000 0x0010 0x0020 0x0030 0x0040 0x0050 0x0060 0x0070 0x0080 0x0090 0x00a0 0x00b0 0x00c0 0x00d0 0x00e0 0x00f0 Supported RX frame types: * IBSS: 0x00d0 * managed: 0x0040 0x00d0 * AP: 0x0000 0x0020 0x0040 0x00a0 0x00b0 0x00c0 0x00d0 * AP/VLAN: 0x0000 0x0020 0x0040 0x00a0 0x00b0 0x00c0 0x00d0 * mesh point: 0x00b0 0x00c0 0x00d0 * P2P-client: 0x0040 0x00d0 * P2P-GO: 0x0000 0x0020 0x0040 0x00a0 0x00b0 0x00c0 0x00d0 Device supports RSN-IBSS.

    Read the article

  • DisplayPort -> DVI Adapter, Active or Passive?

    - by Aren B
    I read somewhere that you only need an active adapter (usb powered) if you want resolutions greater than 1920x1200. I also heard from someone that you need it when running triple-monitor because more than two displays drains too much power. So to connect a 3rd monitor @ 1920x1200 to my video card's DisplayPort Port, do I need to spend the extra $100 and buy the active adapter?

    Read the article

  • Hudson as passive server

    - by Arnab Sen Gupta
    Is it possible to use Hudson only as a passive server,i.e, not using it for building purpose instead sending build results generated by some other tool in maybe XML format and using Hudson to only display the results??

    Read the article

  • Exception Handling in MVP Passive View

    - by ilmatte
    Hello, I'm wondering what's the preferred way to manage exceptions in an MVP implemented with a Passive View. There's a discussion in my company about putting try/catch blocks in the presenter or only in the view. In my opinion the logical top level caller is the presenter (even if the actual one is the view). Moreover I can test the presenter and not the view. This is the reason why I prefer to define a method in the view interface: IView.ShowError(error) and invoke it from the catch blocks in the presenter: try { } catch (Exception exception) { ...log exception... view.ShowError("An error occurred") } In this way the developers of future views can safely forget to implement exception handling but the IView interface force them to implement a ShowError method. The drawback is that if I want to feel completely safe I need to add redundant try/catch blocks in the view. The other way would be to add try catch blocks only in the views and not introducing the showerror method in the view interface. What do you suggest?

    Read the article

  • Webforms MVP Passive View - event handling

    - by ss2k
    Should the view have nothing event specific in its interface and call the presenter plain methods to handle events and not have any official EventHandlers? For instance // ASPX protected void OnSaveButtonClicked(object sender, EventArgs e) { _Presenter.OnSave(); } Or should the view have event EventHandlers defined in its interface and link those up explicitly to control events on the page // View public interface IView { ... event EventHandler Saved; ... } // ASPX Page implementing the view protected override void OnInit(EventArgs e) { base.OnInit(e); SaveButton.Click += delegate { Saved(this, e); }; } // Presenter internal Presenter(IView view,IRepository repository) { _view = view; _repository = repository; view.Saved += Save; } The second seems like a whole lot of plumbing code to add all over. My intention is to understand the benefits of each style and not just a blanket answer of which to use. My main goals is clarity and high value testability. Testability overall is important, but I wouldn't sacrifice design simplicity and clarity to be able to add another type of test that doesn't lead to too much gain over the test cases already possible with a simpler design. If a design choice does off more testability please include an example (pseudo code is fine) of the type of test it can now offer so I can make my decision if I value that type of extra test enough. Thanks!

    Read the article

  • You do not need a separate SQL Server license for a Standby or Passive server - this Microsoft White Paper explains all

    - by tonyrogerson
    If you were in any doubt at all that you need to license Standby / Passive Failover servers then the White Paper “Do Not Pay Too Much for Your Database Licensing” will settle those doubts. I’ve had debate before people thinking you can only have a single instance as a standby machine, that’s just wrong; it would mean you could have a scenario where you had a 2 node active/passive cluster with database mirroring and log shipping (a total of 4 SQL Server instances) – in that set up you only need to buy one physical license so long as the standby nodes have the same or less physical processors (cores are irrelevant). So next time your supplier suggests you need a license for your standby box tell them you don’t and educate them by pointing them to the white paper. For clarity I’ve copied the extract below from the White Paper. Extract from “Do Not Pay Too Much for Your Database Licensing” Standby Server Customers often implement standby server to make sure the application continues to function in case primary server fails. Standby server continuously receives updates from the primary server and will take over the role of primary server in case of failure in the primary server. Following are comparisons of how each vendor supports standby server licensing. SQL Server Customers does not need to license standby (or passive) server provided that the number of processors in the standby server is equal or less than those in the active server. Oracle DB Oracle requires customer to fully license both active and standby servers even though the standby server is essentially idle most of the time. IBM DB2 IBM licensing on standby server is quite complicated and is different for every editions of DB2. For Enterprise Edition, a minimum of 100 PVUs or 25 Authorized User is needed to license standby server.   The following graph compares prices based on a database application with two processors (dual-core) and 25 users with one standby server. [chart snipped]  Note   All prices are based on newest Intel Xeon Nehalem processor database pricing for purchases within the United States and are in United States dollars. Pricing is based on information available on vendor Web sites for Enterprise Edition. Microsoft SQL Server Enterprise Edition 25 users (CALs) x $164 / CAL + $8,592 / Server = $12,692 (no need to license standby server) Oracle Enterprise Edition (base license without options) Named User Plus minimum (25 Named Users Plus per Core) = 25 x 2 = 50 Named Users Plus x $950 / Named Users Plus x 2 servers = $95,000 IBM DB2 Enterprise Edition (base license without feature pack) Need to purchase 125 Authorized User (400 PVUs/100 PVUs = 4 X 25 = 100 Authorized User + 25 Authorized Users for standby server) = 125 Authorized Users x $1,040 / Authorized Users = $130,000  

    Read the article

  • How to get Passive FTP Working Through an Iptables Firewall?

    - by user1133248
    I have an iptables firewall running on a Fedora Linux server that is basically being used as a firewall router and OpenVPN server. That's it. We have been using the same iptables firewall code for YEARS. I did make some changes on 21 December to re-route a mySQL port, but given what has happened I've completely backed those changes out. Sometime after those changes were made and backed out passive FTP, served from a vsftpd process, stopped working. We use a passive ftp client to FLING (that's the name of the ftp client running under Windows! :-) ) images from our remote telescopes to our server. I believe it is something in the firewall code because I can drop the firewall and the FTP file transfer (and connecting to the ftp site with Internet Explorer to see the file list) works. When I raise the iptables firewall, it stops working. Again, this is code that we'd been using for years. However, I felt that maybe there was something I missed, so we had a .bak file from 2009 that I used. Same behavior, passive ftp does not work. So, I went and rebuilt the firewall code line by line to see what line was causing the problem. Everything worked until I put the line -A FORWARD -j DROP in very near the end. Of course, if I am correct, this is the line that basically "turns on" the firewall, saying drop everything except for the exceptions I've made above. However, this line has been in the iptables code probably since 2003. So, I'm at the end of my rope, and I still can't figure out why this has stopped working. I guess I need an expert on iptables configuration. Here is the iptables code (from iptables-save) with comments. # Generated by iptables-save v1.3.8 on Thu Jan 5 18:36:25 2012 *nat # One of the things that I remain ignorant about is what these following three lines # do in both the nat tables (which we're not using on this machine) and the following # filter table. I don't know what the numbers are, but I'm ASSUMING they're port # ranges. # :PREROUTING ACCEPT [7435:551429] :POSTROUTING ACCEPT [6097:354458] :OUTPUT ACCEPT [5:451] COMMIT # Completed on Thu Jan 5 18:36:25 2012 # Generated by iptables-save v1.3.8 on Thu Jan 5 18:36:25 2012 *filter :INPUT ACCEPT [10423:1046501] :FORWARD ACCEPT [0:0] :OUTPUT ACCEPT [15184:16948770] # The following line is for my OpenVPN configuration. -A INPUT -i tun+ -j ACCEPT # In researching this on the Internet I found some iptables code that was supposed to # open the needed ports up. I never needed this before this week, but since passive FTP # was no longer working, I decided to put the code in. The next three lines are part of # that code. -A INPUT -p tcp -m tcp --dport 21 -m state --state NEW,ESTABLISHED -j ACCEPT -A INPUT -p tcp -m tcp --sport 1024:65535 --dport 20 -m state --state ESTABLISHED -j ACCEPT -A INPUT -p tcp -m tcp --sport 1024:65535 --dport 1024:65535 -m state --state RELATED,ESTABLISHED -j ACCEPT # Another line for the OpenVPN configuration. I don't know why the iptables-save mixed # the lines up. -A FORWARD -i tun+ -j ACCEPT # Various forwards for all our services -A FORWARD -s 65.118.148.197 -p tcp -m tcp --dport 3307 -j ACCEPT -A FORWARD -d 65.118.148.197 -p tcp -m tcp --dport 3307 -j ACCEPT -A FORWARD -s 65.118.148.197 -p tcp -m tcp --dport 3306 -j ACCEPT -A FORWARD -d 65.118.148.197 -p tcp -m tcp --dport 3306 -j ACCEPT -A FORWARD -s 65.118.148.196 -p tcp -m tcp --dport 21 -j ACCEPT -A FORWARD -d 65.118.148.196 -p tcp -m tcp --dport 21 -j ACCEPT -A FORWARD -d 65.118.148.196 -p tcp -m tcp --dport 20 -j ACCEPT -A FORWARD -s 65.118.148.196 -p tcp -m tcp --dport 20 -j ACCEPT -A FORWARD -s 65.118.148.196 -p tcp -m tcp --dport 7191 -j ACCEPT -A FORWARD -d 65.118.148.196 -p tcp -m tcp --dport 7191 -j ACCEPT -A FORWARD -s 65.118.148.196 -p tcp -m tcp --dport 46000:46999 -j ACCEPT -A FORWARD -d 65.118.148.196 -p tcp -m tcp --dport 46000:46999 -j ACCEPT -A FORWARD -s 65.118.148.0/255.255.255.0 -j ACCEPT -A FORWARD -d 65.118.148.196 -p udp -m udp --dport 53 -j ACCEPT -A FORWARD -s 65.118.148.196 -p udp -m udp --dport 53 -j ACCEPT -A FORWARD -d 65.118.148.196 -p tcp -m tcp --dport 53 -j ACCEPT -A FORWARD -s 65.118.148.196 -p tcp -m tcp --dport 53 -j ACCEPT -A FORWARD -d 65.118.148.196 -p udp -m udp --dport 25 -j ACCEPT -A FORWARD -s 65.118.148.196 -p udp -m udp --dport 25 -j ACCEPT -A FORWARD -d 65.118.148.196 -p tcp -m tcp --dport 42 -j ACCEPT -A FORWARD -s 65.118.148.196 -p tcp -m tcp --dport 42 -j ACCEPT -A FORWARD -s 65.118.148.196 -p tcp -m tcp --dport 25 -j ACCEPT -A FORWARD -d 65.118.148.196 -p tcp -m tcp --dport 25 -j ACCEPT -A FORWARD -d 65.118.148.196 -p tcp -m tcp --dport 80 -j ACCEPT -A FORWARD -s 65.118.148.196 -p tcp -m tcp --dport 80 -j ACCEPT -A FORWARD -d 65.118.148.204 -p tcp -m tcp --dport 80 -j ACCEPT -A FORWARD -s 65.118.148.204 -p tcp -m tcp --dport 80 -j ACCEPT -A FORWARD -d 65.118.148.196 -p tcp -m tcp --dport 6667 -j ACCEPT -A FORWARD -s 65.118.148.196 -p tcp -m tcp --dport 6667 -j ACCEPT -A FORWARD -s 65.96.214.242 -p tcp -m tcp --dport 22 -j ACCEPT -A FORWARD -s 192.68.148.66 -p tcp -m tcp --dport 22 -j ACCEPT -A FORWARD -m state --state RELATED,ESTABLISHED -j ACCEPT # "The line" that causes passive ftp to stop working. Insofar as I can tell, everything # else seems to work - ssh, telnet, mysql, httpd. -A FORWARD -j DROP -A FORWARD -p icmp -j ACCEPT # The following code is again part of my attempt to put in code that would cause passive # ftp to work. I don't know why iptables-save scattered it about like this. -A OUTPUT -p tcp -m tcp --sport 21 -m state --state ESTABLISHED -j ACCEPT -A OUTPUT -p tcp -m tcp --sport 20 --dport 1024:65535 -m state --state RELATED,ESTABLISHED -j ACCEPT -A OUTPUT -p tcp -m tcp --sport 1024:65535 --dport 1024:65535 -m state --state ESTABLISHED -j ACCEPT COMMIT # Completed on Thu Jan 5 18:36:25 2012 So, with all that prelude, my basic question is: How can I get passive ftp to work behind an iptables firewall? As you can see, I've tried to get it working (again) and tried to do some research on the issue, but have come up...short. Any answers would be appreciated by both me and various variable star astronomers around the world! THANKS! -Richard "Doc" Kinne, American Assoc. of Variable Star Observers, [email protected]

    Read the article

  • EPM 11.1.2 - Configure a data source to support Essbase failover in active-passive clustering mode

    - by Ahmed A
    To configure a data source to support Essbase fail-over in active-passive clustering mode, replace the Essbase Server name value with the APS URL followed by the Essbase cluster name; for example, if the APS URL is http://<hostname>:13090/aps and the Essbase cluster name is EssbaseCluster-1, then the value in the Essbase Server name field would be:http://<hostname>:13090/aps/Essbase?clusterName=EssbaseCluster-1Note: Entering the Essbase cluster name without the APS URL in the Essbase Server name field is not supported in this release.

    Read the article

  • FTP not listing directory NcFTP PASV

    - by Jacob Talbot
    I am attempting to setup Multicraft on my server, all is running smoothly however the FTP won't allow anyone to connect from a remote FTP client, where net2ftp will work smoothly from a remote location. I have included the transcript from my FTP client, Transmit below to give you an idea of what's going on. I have disabled iptables as well, and still no luck either way. Transmit 4.1.7 (x86_64) Session Transcript [Version 10.8.2 (Build 12C54)] (21/10/12 11:23 PM) LibNcFTP 3.2.3 (July 23, 2009) compiled for UNIX 220: Multicraft 1.7.1 FTP server Connected to ateam.bn-mc.net. Cmd: USER jacob.9 331: Username ok, send password. Cmd: PASS xxxxxxxx 230: Login successful Cmd: TYPE A 200: Type set to: ASCII. Logged in to ateam.bn-mc.net as jacob.9. Cmd: SYST 215: UNIX Type: L8 Cmd: FEAT 211: Features supported: EPRT EPSV MDTM MLSD MLST type*;perm*;size*;modify*;unique*;unix.mode;unix.uid;unix.gid; REST STREAM SIZE TVFS UTF8 End FEAT. Cmd: OPTS UTF8 ON 200: OK Cmd: PWD 257: "/" is the current directory. Cmd: PASV Could not read reply from control connection -- timed out. (SReadline 1)

    Read the article

  • IIS 7.5 What am I doing wrong?

    - by chugh97
    In IIS 7.5 under Windows 7 Utilmate, I have an application which is configured for authentication as follows: Anonymous & Windows In the ASP.NET Website, I have turned Forms authentication and identity impersonate = true I also deny any anonymous users. <authentication mode="Forms"> </authentication> <identity impersonate="true"/> <authorization> <deny user="?"> </authorization> IIS complains. What am I doing wrong... What I want to achieve :I want the windows Logged On User so I can build a FormsAuthentication ticket and pass it to a Passive STS. So in IIS I have anonymous and windows...If have only windows ticked, I cannot go onto the Login.aspx page as I have an extra parameter to be passed from there. So now in webconfig, I then disable anonymous users by saying deny user="?" , so it leaves me with the authenticated windows user but using Forms Authentication.You know what I mean??

    Read the article

  • Clusterware 11gR2 &ndash; Setting up an Active/Passive failover configuration

    - by Gilles Haro
    Oracle is providing a large range of interesting solutions to ensure High Availability of the database. Dataguard, RAC or even both configurations (as recommended by Oracle for a Maximum Available Architecture - MAA) are the most frequently found and used solutions. But, when it comes to protecting a system with an Active/Passive architecture with failover capabilities, people often thinks to other expensive third party cluster systems. Oracle Clusterware technology, which comes along at no extra-cost with Oracle Database or Oracle Unbreakable Linux, is - in the knowing of most people - often linked to Oracle RAC and therefore, is seldom used to implement failover solutions. Oracle Clusterware 11gR2  (a part of Oracle 11gR2 Grid Infrastructure)  provides a comprehensive framework to setup automatic failover configurations. It is actually possible to make "failover-able'", and then to protect, almost any kind of application (from the simple xclock to the most complex Application Server). Quoting Oracle: “Oracle Clusterware is a portable cluster software that allows clustering of single servers so that they cooperate as a single system. Oracle Clusterware also provides the required infrastructure for Oracle Real Application Clusters (RAC). In addition Oracle Clusterware enables the protection of any Oracle application or any other kind of application within a cluster.” In the next couple of lines, I will try to present the different steps to achieve this goal : Have a fully operational 11gR2 database protected by automatic failover capabilities. I assume you are fluent in installing Oracle Database 11gR2, Oracle Grid Infrastructure 11gR2 on a Linux system and that ASM is not a problem for you (as I am using it as a shared storage). If not, please have a look at Oracle Documentation. As often, I made my tests using an Oracle VirtualBox environment. The scripts are tested and functional on my system. Unfortunately, there can always be a typo or a mistake. This blog entry does not replace a course around the Clusterware Framework. I just hope it will let you see how powerful it is and that it will give you the whilst to go further with it...  Note : This entry has been revised (rev.2) following comments from Philip Newlan. Prerequisite 2 Linux boxes (OELCluster01 and OELCluster02) at the same OS level. I used OEL 5 Update 5 with an Enterprise Kernel. Shared Storage (SAN). On my VirtualBox system, I used Openfiler to simulate the SAN Oracle 11gR2 Database (11.2.0.1) Oracle 11gR2 Grid Infrastructure (11.2.0.1)   Step 1 - Install the software Using asmlib, create 3 ASM disks (ASM_CRS, ASM_DTA and ASM_FRA) Install Grid Infrastructure for a cluster (OELCluster01 and OELCluster02 are the 2 nodes of the cluster) Use ASM_CRS to store Voting Disk and OCR. Use SCAN. Install Oracle Database Standalone binaries on both nodes. Use asmca to check/mount the disk groups on 2 nodes Use dbca to create and configure a database on the primary node Let's name it DB11G. Copy the pfile, password file to the second node. Create adump directoty on the second node.   Step 2 - Setup the resource to be protected After its creation with dbca, the database is automatically protected by the Oracle Restart technology available with Grid Infrastructure. Consequently, it restarts automatically (if possible) after a crash (ex: kill -9 smon). A database resource has been created for that in the Cluster Registry. We can observe this with the command : crsctl status resource that shows and ora.dba11g.db entry. Let's save the definition of this resource, for future use : mkdir -p /crs/11.2.0/HA_scripts chown oracle:oinstall /crs/11.2.0/HA_scripts crsctl status resource ora.db11g.db -p > /crs/11.2.0/HA_scripts/myResource.txt Although very interesting, Oracle Restart is not cluster aware and cannot restart the database on any other node of the cluster. So, let's remove it from the OCR definitions, we don't need it ! srvctl stop database -d DB11G srvctl remove database -d DB11G Instead of it, we need to create a new resource of a more general type : cluster_resource. Here are the steps to achieve this : Create an action script :  /crs/11.2.0/HA_scripts/my_ActivePassive_Cluster.sh #!/bin/bash export ORACLE_HOME=/oracle/product/11.2.0/dbhome_1 export ORACLE_SID=DB11G case $1 in 'start')   $ORACLE_HOME/bin/sqlplus /nolog <<EOF   connect / as sysdba   startup EOF   RET=0   ;; 'stop')   $ORACLE_HOME/bin/sqlplus /nolog <<EOF   connect / as sysdba   shutdown immediate EOF   RET=0   ;; 'clean')   $ORACLE_HOME/bin/sqlplus /nolog <<EOF   connect / as sysdba   shutdown abort    ##for i in `ps -ef | grep -i $ORACLE_SID | awk '{print $2}' ` ;do kill -9 $i; done EOF   RET=0   ;; 'check')    ok=`ps -ef | grep smon | grep $ORACLE_SID | wc -l`    if [ $ok = 0 ]; then      RET=1    else      RET=0    fi    ;; '*')      RET=0   ;; esac if [ $RET -eq 0 ]; then    exit 0 else    exit 1 fi   This script must provide, at least, methods to start, stop, clean and check the database. It is self-explaining and contains nothing special. Just be aware that it must be runnable (+x), it runs as Oracle user (because of the ACL property - see later) and needs to know about the environment. Also make sure it exists on every node of the cluster. Moreover, as of 11.2, the clean method is mandatory. It must provide the “last gasp clean up”, for example, a shutdown abort or a kill –9 of all the remaining processes. chmod +x /crs/11.2.0/HA_scripts/my_ActivePassive_Cluster.sh scp  /crs/11.2.0/HA_scripts/my_ActivePassive_Cluster.sh   oracle@OELCluster02:/crs/11.2.0/HA_scripts Create a new resource file, based on the information we got from previous  myResource.txt . Name it myNewResource.txt. myResource.txt  is shown below. As we can see, it defines an ora.database.type resource, named ora.db11g.db. A lot of properties are related to this type of resource and do not need to be used for a cluster_resource. NAME=ora.db11g.db TYPE=ora.database.type ACL=owner:oracle:rwx,pgrp:oinstall:rwx,other::r-- ACTION_FAILURE_TEMPLATE= ACTION_SCRIPT= ACTIVE_PLACEMENT=1 AGENT_FILENAME=%CRS_HOME%/bin/oraagent%CRS_EXE_SUFFIX% AUTO_START=restore CARDINALITY=1 CHECK_INTERVAL=1 CHECK_TIMEOUT=600 CLUSTER_DATABASE=false DB_UNIQUE_NAME=DB11G DEFAULT_TEMPLATE=PROPERTY(RESOURCE_CLASS=database) PROPERTY(DB_UNIQUE_NAME= CONCAT(PARSE(%NAME%, ., 2), %USR_ORA_DOMAIN%, .)) ELEMENT(INSTANCE_NAME= %GEN_USR_ORA_INST_NAME%) DEGREE=1 DESCRIPTION=Oracle Database resource ENABLED=1 FAILOVER_DELAY=0 FAILURE_INTERVAL=60 FAILURE_THRESHOLD=1 GEN_AUDIT_FILE_DEST=/oracle/admin/DB11G/adump GEN_USR_ORA_INST_NAME= GEN_USR_ORA_INST_NAME@SERVERNAME(oelcluster01)=DB11G HOSTING_MEMBERS= INSTANCE_FAILOVER=0 LOAD=1 LOGGING_LEVEL=1 MANAGEMENT_POLICY=AUTOMATIC NLS_LANG= NOT_RESTARTING_TEMPLATE= OFFLINE_CHECK_INTERVAL=0 ORACLE_HOME=/oracle/product/11.2.0/dbhome_1 PLACEMENT=restricted PROFILE_CHANGE_TEMPLATE= RESTART_ATTEMPTS=2 ROLE=PRIMARY SCRIPT_TIMEOUT=60 SERVER_POOLS=ora.DB11G SPFILE=+DTA/DB11G/spfileDB11G.ora START_DEPENDENCIES=hard(ora.DTA.dg,ora.FRA.dg) weak(type:ora.listener.type,uniform:ora.ons,uniform:ora.eons) pullup(ora.DTA.dg,ora.FRA.dg) START_TIMEOUT=600 STATE_CHANGE_TEMPLATE= STOP_DEPENDENCIES=hard(intermediate:ora.asm,shutdown:ora.DTA.dg,shutdown:ora.FRA.dg) STOP_TIMEOUT=600 UPTIME_THRESHOLD=1h USR_ORA_DB_NAME=DB11G USR_ORA_DOMAIN=haroland USR_ORA_ENV= USR_ORA_FLAGS= USR_ORA_INST_NAME=DB11G USR_ORA_OPEN_MODE=open USR_ORA_OPI=false USR_ORA_STOP_MODE=immediate VERSION=11.2.0.1.0 I removed database type related entries from myResource.txt and modified some other to produce the following myNewResource.txt. Notice the NAME property that should not have the ora. prefix Notice the TYPE property that is not ora.database.type but cluster_resource. Notice the definition of ACTION_SCRIPT. Notice the HOSTING_MEMBERS that enumerates the members of the cluster (as returned by the olsnodes command). NAME=DB11G.db TYPE=cluster_resource DESCRIPTION=Oracle Database resource ACL=owner:oracle:rwx,pgrp:oinstall:rwx,other::r-- ACTION_SCRIPT=/crs/11.2.0/HA_scripts/my_ActivePassive_Cluster.sh PLACEMENT=restricted ACTIVE_PLACEMENT=0 AUTO_START=restore CARDINALITY=1 CHECK_INTERVAL=10 DEGREE=1 ENABLED=1 HOSTING_MEMBERS=oelcluster01 oelcluster02 LOGGING_LEVEL=1 RESTART_ATTEMPTS=1 START_DEPENDENCIES=hard(ora.DTA.dg,ora.FRA.dg) weak(type:ora.listener.type,uniform:ora.ons,uniform:ora.eons) pullup(ora.DTA.dg,ora.FRA.dg) START_TIMEOUT=600 STOP_DEPENDENCIES=hard(intermediate:ora.asm,shutdown:ora.DTA.dg,shutdown:ora.FRA.dg) STOP_TIMEOUT=600 UPTIME_THRESHOLD=1h Register the resource. Take care of the resource type. It needs to be a cluster_resource and not a ora.database.type resource (Oracle recommendation) .   crsctl add resource DB11G.db  -type cluster_resource -file /crs/11.2.0/HA_scripts/myNewResource.txt Step 3 - Start the resource crsctl start resource DB11G.db This command launches the ACTION_SCRIPT with a start and a check parameter on the primary node of the cluster. Step 4 - Test this We will test the setup using 2 methods. crsctl relocate resource DB11G.db This command calls the ACTION_SCRIPT  (on the two nodes)  to stop the database on the active node and start it on the other node. Once done, we can revert back to the original node, but, this time we can use a more "MS$ like" method :Turn off the server on which the database is running. After short delay, you should observe that the database is relocated on node 1. Conclusion Once the software installed and the standalone database created (which is a rather common and usual task), the steps to reach the objective are quite easy : Create an executable action script on every node of the cluster. Create a resource file. Create/Register the resource with OCR using the resource file. Start the resource. This solution is a very interesting alternative to licensable third party solutions. References Clusterware 11gR2 documentation Oracle Clusterware Resource Reference Clusterware for Unbreakable Linux Using Oracle Clusterware to Protect A Single Instance Oracle Database 11gR1 (to have an idea of complexity) Oracle Clusterware on OTN   Gilles Haro Technical Expert - Core Technology, Oracle Consulting   

    Read the article

  • Clusterware 11gR2 &ndash; Setting up an Active/Passive failover configuration

    - by Gilles Haro
    Oracle provides many interesting ways to ensure High Availability. Dataguard configurations, RAC configurations or even both (as recommended for a Maximum Available Architecture - MAA) are the most frequently found. But when it comes to protecting a system with an Active/Passive architecture with failover capabilities, one often thinks to expensive third party cluster systems. Oracle Clusterware technology, which comes free with Oracle Database, is – in the knowing of most people - often linked to Oracle RAC and therefore, is rarely used to implement failover solutions. 11gR2 Clusterware – which is part of Oracle Grid Infrastructure - provides a comprehensive framework to setup automatic failover configurations. It is actually possible to make “failover-able'” and, therefore to protect, almost every kind of application (from xclock to the more complex Application Server) In the next couple of lines, I will try to present the different steps to achieve this goal : Have a fully operational 11gR2 database protected by automatic failover capabilities. I assume you are fluent in installing Oracle Database 11gR2, Oracle Grid Infrastructure 11gR2 on a Linux system and that ASM is not a problem for you (as I am using it as a shared storage). If not, please have a look at Oracle Documentation. As often, I made my tests using an Oracle VirtualBox environment. The scripts are tested and functional. Unfortunately, there can always be a typo or a mistake. This blog entry is not a course around the Clusterware Framework. I just hope it will let you see how powerful it is and that it will give you the whilst to go further with it…   Prerequisite 2 Linux boxes (OELCluster01 and OELCluster02) at the same OS level. I used OEL 5 Update 5 with Enterprise Kernel. Shared Storage (SAN). On my VirtualBox system, I used Openfiler to simulate the SAN Oracle 11gR2 Database (11.2.0.1) Oracle 11gR2 Grid Infrastructure (11.2.0.1)   Step 1 – Install the software Using asmlib, create 3 ASM disks (ASM_CRS, ASM_DTA and ASM_FRA) Install Grid Infrastructure for a cluster (OELCluster01 and OELCluster02 are the 2 nodes of the cluster) Use ASM_CRS to store Voting Disk and OCR. Use SCAN. Install Oracle Database Standalone binaries on both nodes. Use asmca to check/mount the disk groups on 2 nodes Use dbca to create and configure a database on the primary node Let’s name it DB11G. Copy the pfile, password file to the second node. Create adump directoty on the second node.   Step 2 - Setup the resource to be protected After its creation with dbca, the database is automatically protected by the Oracle Restart technology available with Grid Infrastructure. Consequently, it restarts automatically (if possible) after a crash (ex: kill –9 smon). A database resource has been created for that in the Cluster Registry. We can observe this with the command : crsctl status resource that shows and ora.dba11g.db entry. Let’s save the definition of this resource, for future use : mkdir –p /crs/11.2.0/HA_scripts chown oracle:oinstall /crs/11.2.0/HA_scripts crsctl status resource ora.db11g.db -p > /crs/11.2.0/HA_scripts/myResource.txt Although very interesting, Oracle Restart is not cluster aware and cannot restart the database on any other node of the cluster. So, let’s remove it from the OCR definitions, we don’t need it ! srvctl stop database -d DB11G srvctl remove database -d DB11G Instead of it, we need to create a new resource of a more general type : cluster_resource. Here are the steps to achieve this : Create an action script :  /crs/11.2.0/HA_scripts/my_ActivePassive_Cluster.sh #!/bin/bash export ORACLE_HOME=/oracle/product/11.2.0/dbhome_1 export ORACLE_SID=DB11G case $1 in 'start')   $ORACLE_HOME/bin/sqlplus /nolog <<EOF   connect / as sysdba   startup EOF   RET=0   ;; 'stop')   $ORACLE_HOME/bin/sqlplus /nolog <<EOF   connect / as sysdba   shutdown immediate EOF   RET=0   ;; 'check')    ok=`ps -ef | grep smon | grep $ORACLE_SID | wc -l`    if [ $ok = 0 ]; then      RET=1    else      RET=0    fi    ;; '*')      RET=0   ;; esac if [ $RET -eq 0 ]; then    exit 0 else    exit 1 fi   This script must provide, at least, methods to start, stop and check the database. It is self-explaining and contains nothing special. Just be aware that it is run as Oracle user (because of the ACL property – see later) and needs to know about the environment. It also needs to be present on every node of the cluster. chmod +x /crs/11.2.0/HA_scripts/my_ActivePassive_Cluster.sh scp  /crs/11.2.0/HA_scripts/my_ActivePassive_Cluster.sh   oracle@OELCluster02:/crs/11.2.0/HA_scripts Create a new resource file, based on the information we got from previous  myResource.txt . Name it myNewResource.txt. myResource.txt  is shown below. As we can see, it defines an ora.database.type resource, named ora.db11g.db. A lot of properties are related to this type of resource and do not need to be used for a cluster_resource. NAME=ora.db11g.db TYPE=ora.database.type ACL=owner:oracle:rwx,pgrp:oinstall:rwx,other::r-- ACTION_FAILURE_TEMPLATE= ACTION_SCRIPT= ACTIVE_PLACEMENT=1 AGENT_FILENAME=%CRS_HOME%/bin/oraagent%CRS_EXE_SUFFIX% AUTO_START=restore CARDINALITY=1 CHECK_INTERVAL=1 CHECK_TIMEOUT=600 CLUSTER_DATABASE=false DB_UNIQUE_NAME=DB11G DEFAULT_TEMPLATE=PROPERTY(RESOURCE_CLASS=database) PROPERTY(DB_UNIQUE_NAME= CONCAT(PARSE(%NAME%, ., 2), %USR_ORA_DOMAIN%, .)) ELEMENT(INSTANCE_NAME= %GEN_USR_ORA_INST_NAME%) DEGREE=1 DESCRIPTION=Oracle Database resource ENABLED=1 FAILOVER_DELAY=0 FAILURE_INTERVAL=60 FAILURE_THRESHOLD=1 GEN_AUDIT_FILE_DEST=/oracle/admin/DB11G/adump GEN_USR_ORA_INST_NAME= GEN_USR_ORA_INST_NAME@SERVERNAME(oelcluster01)=DB11G HOSTING_MEMBERS= INSTANCE_FAILOVER=0 LOAD=1 LOGGING_LEVEL=1 MANAGEMENT_POLICY=AUTOMATIC NLS_LANG= NOT_RESTARTING_TEMPLATE= OFFLINE_CHECK_INTERVAL=0 ORACLE_HOME=/oracle/product/11.2.0/dbhome_1 PLACEMENT=restricted PROFILE_CHANGE_TEMPLATE= RESTART_ATTEMPTS=2 ROLE=PRIMARY SCRIPT_TIMEOUT=60 SERVER_POOLS=ora.DB11G SPFILE=+DTA/DB11G/spfileDB11G.ora START_DEPENDENCIES=hard(ora.DTA.dg,ora.FRA.dg) weak(type:ora.listener.type,uniform:ora.ons,uniform:ora.eons) pullup(ora.DTA.dg,ora.FRA.dg) START_TIMEOUT=600 STATE_CHANGE_TEMPLATE= STOP_DEPENDENCIES=hard(intermediate:ora.asm,shutdown:ora.DTA.dg,shutdown:ora.FRA.dg) STOP_TIMEOUT=600 UPTIME_THRESHOLD=1h USR_ORA_DB_NAME=DB11G USR_ORA_DOMAIN=haroland USR_ORA_ENV= USR_ORA_FLAGS= USR_ORA_INST_NAME=DB11G USR_ORA_OPEN_MODE=open USR_ORA_OPI=false USR_ORA_STOP_MODE=immediate VERSION=11.2.0.1.0 I removed database type related entries from myResource.txt and modified some other to produce the following myNewResource.txt. Notice the NAME property that should not have the ora. prefix Notice the TYPE property that is not ora.database.type but cluster_resource. Notice the definition of ACTION_SCRIPT. Notice the HOSTING_MEMBERS that enumerates the members of the cluster (as returned by the olsnodes command). NAME=DB11G.db TYPE=cluster_resource DESCRIPTION=Oracle Database resource ACL=owner:oracle:rwx,pgrp:oinstall:rwx,other::r-- ACTION_SCRIPT=/crs/11.2.0/HA_scripts/my_ActivePassive_Cluster.sh PLACEMENT=restricted ACTIVE_PLACEMENT=0 AUTO_START=restore CARDINALITY=1 CHECK_INTERVAL=10 DEGREE=1 ENABLED=1 HOSTING_MEMBERS=oelcluster01 oelcluster02 LOGGING_LEVEL=1 RESTART_ATTEMPTS=1 START_DEPENDENCIES=hard(ora.DTA.dg,ora.FRA.dg) weak(type:ora.listener.type,uniform:ora.ons,uniform:ora.eons) pullup(ora.DTA.dg,ora.FRA.dg) START_TIMEOUT=600 STOP_DEPENDENCIES=hard(intermediate:ora.asm,shutdown:ora.DTA.dg,shutdown:ora.FRA.dg) STOP_TIMEOUT=600 UPTIME_THRESHOLD=1h Register the resource. Take care of the resource type. It needs to be a cluster_resource and not a ora.database.type resource (Oracle recommendation) .   crsctl add resource DB11G.db  -type cluster_resource -file /crs/11.2.0/HA_scripts/myNewResource.txt Step 3 - Start the resource crsctl start resource DB11G.db This command launches the ACTION_SCRIPT with a start and a check parameter on the primary node of the cluster. Step 4 - Test this We will test the setup using 2 methods. crsctl relocate resource DB11G.db This command calls the ACTION_SCRIPT  (on the two nodes)  to stop the database on the active node and start it on the other node. Once done, we can revert back to the original node, but, this time we can use a more “MS$ like” method :Turn off the server on which the database is running. After short delay, you should observe that the database is relocated on node 1. Conclusion Once the software installed and the standalone database created (which is a rather common and usual task), the steps to reach the objective are quite easy : Create an executable action script on every node of the cluster. Create a resource file. Create/Register the resource with OCR using the resource file. Start the resource. This solution is a very interesting alternative to licensable third party solutions.   References Clusterware 11gR2 documentation Oracle Clusterware Resource Reference   Gilles Haro Technical Expert - Core Technology, Oracle Consulting   

    Read the article

  • How to set up Zabbix to monitor SQL Server Failover Active-Passive Cluster?

    - by Sebastian Zaklada
    It should be simple, so it is just most likely my approach being totally off and someone will hopefully prod me into the right direction. We have a Zabbix 2.0.3 server instance set up monitoring a bunch of different servers, but now we need to set it up to monitor and notify any alerts in regards to the SQL Server 2008 R2 Failover Active-Passive cluster. Essentially, this is a 2 servers cluster, when only one of its nodes can be "active" at a given time, serving all SQL Server related requests, while the other server just "sleeps" and from the point of anyone logged on on that server - has all of the SQL Server related services in stopped state. We have tried setting up Zabbix agents on both servers, using SQL Server 2005 templates (we could not find any 2008 specific ones and the 2005 ones always seemed to be working just fine for monitoring 2008 R2 instances) and configuring Zabbix server for both of the servers, but we end up having constant alerts for the server being currently the passive one in the cluster. We have been able to look up various methods of actually monitoring the failover, but we have not been able to find any guidance in regards to how to instruct Zabbix, that in this particular case, only one of the servers in the group is expected to be in the online state, while the other can be just discarded and should not raise any alerts. I hope I made myself clear. Thanks for any guidance. I am out of ideas.

    Read the article

  • Is looking for Wi-Fi access points purely passive?

    - by Aric TenEyck
    Say I carry a Wi-Fi enabled phone or laptop through an area where there are WAPs. Assuming that I don't actively try to connect to them or otherwise interact with them, is it possible for the owner of that WAP to know that I was there? I'm asking this in the context of my earlier question: Looking for MACs on the network I was talking with a friend about my newfound ability to detect phones (and other devices with MAC addresses) on the network, and he pointed out that it might be useful to detect unknown phones on the network; I could use that data to track down anyone who was in my house and brought a Wi-Fi phone with them. So, if I set up a logging fake WAP with no security or encryption, can I glean any useful information about the devices that come into the house? Assuming that the thief doesn't actively try to connect...

    Read the article

  • Is looking for Wi-Fi access points purely passive?

    - by Aric TenEyck
    Say I carry a Wi-Fi enabled phone or laptop through an area where there are WAPs. Assuming that I don't actively try to connect to them or otherwise interact with them, is it possible for the owner of that WAP to know that I was there? I'm asking this in the context of my earlier question: Looking for MACs on the network I was talking with a friend about my newfound ability to detect phones (and other devices with MAC addresses) on the network, and he pointed out that it might be useful to detect unknown phones on the network; I could use that data to track down anyone who was in my house and brought a Wi-Fi phone with them. So, if I set up a logging fake WAP with no security or encryption, can I glean any useful information about the devices that come into the house? Assuming that the thief doesn't actively try to connect...

    Read the article

  • How to model dependency injection in UML ?

    - by hjo1620
    I have a Contract class. The contract is valid 1 Jan 2010 - 31 Dec 2010. It can be in state Active or Passive, depending on which date I ask the instance for it's state. ex. if I ask 4 July 2010, it's in state Active, but if I ask 1 Jan 2011, it's in state Passive. Instances are created using constructor dependency injection, i.e. they are either Active or Passive already when created, null is not allowed as a parameter for the internal state member. One initial/created vertex is drawn in UML. I have two arrows, leading out from the initial vertex, one leading to state Active and the other to state Passive. Is this a correct representation of dependency injection in UML ? This is related to http://stackoverflow.com/questions/2779922/how-model-statemachine-when-state-is-dependent-on-a-function which initiated the question on how to model DI in general, in UML.

    Read the article

  • java increase xmx dynamically at runtime

    - by Tomer
    Hi, I have a jvm server in my machine, now I want to have 2 apservers of mine sitting in same machine, however I want the standby one to have a really low amount of memory allocated with xmx because its passive, one the main server (active) goes down I want to allocate more memory to my passive server which is already up without restarting it (I have have them both having too much xmx - note they would consume memory at startup and I cant allow possibility of outOfMemory). So I want passive - low xmx once active goes down I want my passive to receive much more xmx. is there a way for me to achieve that. Thanks

    Read the article

  • EMC VNX iSCSI setup - unsure about SP/port assignment

    - by pauska
    We have a new VNX5300 waiting to get configured, and I need to plan out the network infrastructure before the EMC tech arrives. It has 4x1gbit iSCSI per SP (8 ports in total), and I'd like to get the most out of the performance until we jump over to 10gig iSCSI. From what I can read from the docs - the recommendation is to use only two ports per SP, with 1 active and 1 passive. Why is this? It seems kind of pointless to have quad-port i/o-modules and then recommend to not use more than two of them? Also - I'm a bit unsure about the zoning. The best practices guide state that you should separate each port on each SP from each other on different logical networks. Does this mean that I have to create 4 logical networks to be able to use all 8 ports? It also gives the following example: Does this mean that A0 and B0 should sit on the same physical switch aswell? Won't this make all traffic go on one switch (if both A1 and B1 are passive)? Edit: Another brainpuzzle I don't get it - each host (as in server) should not have more iSCSI bandwidth available than the storage processor. What on earth does this matter? If serverA have 1gbit and serverB have 100mbit, then the resulting bandwith between them is 100mbit. How can this result in some kind of oversubscription? Edit4: Wait, what. Active and passive ports? The VNX runs in a ALUA configuration with asymmetrical active/active.. there shouldn't be any passive ports, only preferred ones..

    Read the article

  • Setting up VSFTPD on AWS EC2 Instance

    - by Robert Ling III
    I'm trying to set up VSFTPD passive hosting on my EC2 instance. I ran through these instructions http://www.synergycode.com/knowledgebase/blog/item/ftp-server-on-amazon-ec2 . However, when I tried to connect in FileZilla, I got Command: CWD /home/lingiii/ftp Response: 250 Directory successfully changed. Command: TYPE I Response: 200 Switching to Binary mode Command: PASV Response: 227 Entering Passive Mode (10,222,206,33,54,184). Status: Server sent passive reply with unroutable address. Using server address instead. Command: LIST Error: Connection timed out Error: Failed to retrieve directory listing Where directory /home/lingiii/ftp is set to wrx permissions for user lingiii, group developers (of which lingiii is a member) AND I'm logging in as user lingiii. Any advice?

    Read the article

  • Boost your infrastructure with Coherence into the Cloud

    - by Nino Guarnacci
    Authors: Nino Guarnacci & Francesco Scarano,  at this URL could be found the original article:  http://blogs.oracle.com/slc/coherence_into_the_cloud_boost. Thinking about the enterprise cloud, come to mind many possible configurations and new opportunities in enterprise environments. Various customers needs that serve as guides to this new trend are often very different, but almost always united by two main objectives: Elasticity of infrastructure both Hardware and Software Investments related to the progressive needs of the current infrastructure Characteristics of innovation and economy. A concrete use case that I worked on recently demanded the fulfillment of two basic requirements of economy and innovation.The client had the need to manage a variety of data cache, which can process complex queries and parallel computational operations, maintaining the caches in a consistent state on different server instances, on which the application was installed.In addition, the customer was looking for a solution that would allow him to manage the likely situations in load peak during certain times of the year.For this reason, the customer requires a replication site, on which convey part of the requests during periods of peak; the desire was, however, to prevent the immobilization of investments in owned hardware-software architectures; so, to respond to this need, it was requested to seek a solution based on Cloud technologies and architectures already offered by the market. Coherence can already now address the requirements of large cache between different nodes in the cluster, providing further technology to search and parallel computing, with the simultaneous use of all hardware infrastructure resources. Moreover, thanks to the functionality of "Push Replication", which can replicate and update the information contained in the cache, even to a site hosted in the cloud, it is satisfied the need to make resilient infrastructure that can be based also on nodes temporarily housed in the Cloud architectures. There are different types of configurations that can be realized using the functionality "Push-Replication" of Coherence. Configurations can be either: Active - Passive  Hub and Spoke Active - Active Multi Master Centralized Replication Whereas the architecture of this particular project consists of two sites (Site 1 and Site Cloud), between which only Site 1 is enabled to write into the cache, it was decided to adopt an Active-Passive Configuration type (Hub and Spoke). If, however, the requirement should change over time, it will be particularly easy to change this configuration in an Active-Active configuration type. Although very simple, the small sample in this post, inspired by the specific project is effective, to better understand the features and capabilities of Coherence and its configurations. Let's create two distinct coherence cluster, located at miles apart, on two different domain contexts, one of them "hosted" at home (on-premise) and the other one hosted by any cloud provider on the network (or just the same laptop to test it :)). These two clusters, which we call Site 1 and Site Cloud, will contain the necessary information, so a simple client can insert data only into the Site 1. On both sites will be subscribed a listener, who listens to the variations of specific objects within the various caches. To implement these features, you need 4 simple classes: CachedResponse.java Represents the POJO class that will be inserted into the cache, and fulfills the task of containing useful information about the hypothetical links navigation ResponseSimulatorHelper.java Represents a link simulator, which has the task of randomly creating objects of type CachedResponse that will be added into the caches CacheCommands.java Represents the model of our example, because it is responsible for receiving instructions from the controller and performing basic operations against the cache, such as insert, delete, update, listening, objects within the cache Shell.java It is our controller, which give commands to be executed within the cache of the two Sites So, summarily, we execute the java class "Shell", asking it to put into the cache 100 objects of type "CachedResponse" through the java class "CacheCommands", then the simulator "ResponseSimulatorHelper" will randomly create new instances of objects "CachedResponse ". Finally, the Shell class will listen to for events occurring within the cache on the Site Cloud, while insertions and deletions are performed on Site 1. Now, we realize the two configurations of two respective sites / cluster: Site 1 and Site Cloud.For the Site 1 we define a cache of type "distributed" with features of "read and write", using the cache class store for the "push replication", a functionality offered by the project "incubator" of Oracle Coherence.For the "Site Cloud" we expect even the definition of “distributed” cache type with tcp proxy feature enabled, so it can receive updates from Site 1.  Coherence Cache Config XML file for "storage node" on "Site 1" site1-prod-cache-config.xml Coherence Cache Config XML file for "storage node" on "Site Cloud" site2-prod-cache-config.xml For two clients "Shell" which will connect respectively to the two clusters we have provided two easy access configurations.  Coherence Cache Config XML file for Shell on "Site 1" site1-shell-prod-cache-config.xml Coherence Cache Config XML file for Shell on "Site Cloud" site2-shell-prod-cache-config.xml Now, we just have to get everything and run our tests. To start at least one "storage" node (which holds the data) for the "Cloud Site", we can run the standard class  provided OOTB by Oracle Coherence com.tangosol.net.DefaultCacheServer with the following parameters and values:-Xmx128m-Xms64m-Dcom.sun.management.jmxremote -Dtangosol.coherence.management=all -Dtangosol.coherence.management.remote=true -Dtangosol.coherence.distributed.localstorage=true -Dtangosol.coherence.cacheconfig=config/site2-prod-cache-config.xml-Dtangosol.coherence.clusterport=9002-Dtangosol.coherence.site=SiteCloud To start at least one "storage" node (which holds the data) for the "Site 1", we can perform again the standard class provided by Coherence  com.tangosol.net.DefaultCacheServer with the following parameters and values:-Xmx128m-Xms64m-Dcom.sun.management.jmxremote -Dtangosol.coherence.management=all -Dtangosol.coherence.management.remote=true -Dtangosol.coherence.distributed.localstorage=true -Dtangosol.coherence.cacheconfig=config/site1-prod-cache-config.xml-Dtangosol.coherence.clusterport=9001-Dtangosol.coherence.site=Site1 Then, we start the first client "Shell" for the "Cloud Site", launching the java class it.javac.Shell  using these parameters and values: -Xmx64m-Xms64m-Dcom.sun.management.jmxremote -Dtangosol.coherence.management=all -Dtangosol.coherence.management.remote=true -Dtangosol.coherence.distributed.localstorage=false -Dtangosol.coherence.cacheconfig=config/site2-shell-prod-cache-config.xml-Dtangosol.coherence.clusterport=9002-Dtangosol.coherence.site=SiteCloud Finally, we start the second client "Shell" for the "Site 1", re-launching a new instance of class  it.javac.Shell  using  the following parameters and values: -Xmx64m-Xms64m-Dcom.sun.management.jmxremote -Dtangosol.coherence.management=all -Dtangosol.coherence.management.remote=true -Dtangosol.coherence.distributed.localstorage=false -Dtangosol.coherence.cacheconfig=config/site1-shell-prod-cache-config.xml-Dtangosol.coherence.clusterport=9001-Dtangosol.coherence.site=Site1  And now, let’s execute some tests to validate and better understand our configuration. TEST 1The purpose of this test is to load the objects into the "Site 1" cache and seeing how many objects are cached on the "Site Cloud". Within the "Shell" launched with parameters to access the "Site 1", let’s write and run the command: load test/100 Within the "Shell" launched with parameters to access the "Site Cloud" let’s write and run the command: size passive-cache Expected result If all is OK, the first "Shell" has uploaded 100 objects into a cache named "test"; consequently the "push-replication" functionality has updated the "Site Cloud" by sending the 100 objects to the second cluster where they will have been posted into a respective cache, which we named "passive-cache". TEST 2The purpose of this test is to listen to deleting and adding events happening on the "Site 1" and that are replicated within the cache on "Cloud Site". In the "Shell" launched with parameters to access the "Site Cloud" let’s write and run the command: listen passive-cache/name like '%' or a "cohql" query, with your preferred parameters In the "Shell" launched with parameters to access the "Site 1" let’s write and run the following commands: load test/10 load test2/20 delete test/50 Expected result If all is OK, the "Shell" to Site Cloud let us to listen to all the add and delete events within the cache "cache-passive", whose objects satisfy the query condition "name like '%' " (ie, every objects in the cache; you could change the tests and create different queries).Through the Shell to "Site 1" we launched the commands to add and to delete objects on different caches (test and test2). With the "Shell" running on "Site Cloud" we got the evidence (displayed or printed, or in a log file) that its cache has been filled with events and related objects generated by commands executed from the" Shell "on" Site 1 ", thanks to "push-replication" feature.  Other tests can be performed, such as, for example, the subscription to the events on the "Site 1" too, using different "cohql" queries, changing the cache configuration,  to effectively demonstrate both the potentiality and  the versatility produced by these different configurations, even in the cloud, as in our case. More information on how to configure Coherence "Push Replication" can be found in the Oracle Coherence Incubator project documentation at the following link: http://coherence.oracle.com/display/INC10/Home More information on Oracle Coherence "In Memory Data Grid" can be found at the following link: http://www.oracle.com/technetwork/middleware/coherence/overview/index.html To download and execute the whole sources and configurations of the example explained in the above post,  click here to download them; After download the last available version of the Push-Replication Pattern library implementation from the Oracle Coherence Incubator site, and download also the related and required version of Oracle Coherence. For simplicity the required .jarS to execute the example (that can be found into the Push-Replication-Pattern  download and Coherence Distribution download) are: activemq-core-5.3.1.jar activemq-protobuf-1.0.jar aopalliance-1.0.jar coherence-commandpattern-2.8.4.32329.jar coherence-common-2.2.0.32329.jar coherence-eventdistributionpattern-1.2.0.32329.jar coherence-functorpattern-1.5.4.32329.jar coherence-messagingpattern-2.8.4.32329.jar coherence-processingpattern-1.4.4.32329.jar coherence-pushreplicationpattern-4.0.4.32329.jar coherence-rest.jar coherence.jar commons-logging-1.1.jar commons-logging-api-1.1.jar commons-net-2.0.jar geronimo-j2ee-management_1.0_spec-1.0.jar geronimo-jms_1.1_spec-1.1.1.jar http.jar jackson-all-1.8.1.jar je.jar jersey-core-1.8.jar jersey-json-1.8.jar jersey-server-1.8.jar jl1.0.jar kahadb-5.3.1.jar miglayout-3.6.3.jar org.osgi.core-4.1.0.jar spring-beans-2.5.6.jar spring-context-2.5.6.jar spring-core-2.5.6.jar spring-osgi-core-1.2.1.jar spring-osgi-io-1.2.1.jar At this URL could be found the original article: http://blogs.oracle.com/slc/coherence_into_the_cloud_boost Authors: Nino Guarnacci & Francesco Scarano

    Read the article

< Previous Page | 1 2 3 4 5 6 7 8 9 10 11 12  | Next Page >