Test Network Connection Between Remote and Instrument Computers » History » Version 33
Anchi Cheng, 05/09/2018 02:03 PM
1 | 20 | Anchi Cheng | h1. Test Network Connection Between Remote and Instrument Computers |
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5 | 20 | Anchi Cheng | By far the biggest installation problem comes from network connection is block at the microscope/camera computer from the remote computer where the main Leginon program is run. Here is a test to do before trying to start leginon operation at the remote computer. Leginon bulletin board has a thread that has "various problems and solutions":http://emg.nysbc.org/boards/6/topics/3 from users. |
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9 | h2. Start a Test Launcher on the Microscope Computer |
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13 | 11 | Amber Herold | # scope> go to the location where Leginon is installed, generally |
14 | 27 | Anchi Cheng | <pre>C:\Python27\Lib\site-packages\Leginon\</pre> |
15 | 11 | Amber Herold | # scope> double click on test1.py. You should see something like this: |
16 | <pre>INFO localtransport server created at location {'instance': <localtransport.Server object at 0x40e614cc>} |
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17 | 1 | Amber Herold | INFO tcptransport server created at location {'hostname': 'myscope', 'port': 49152} |
18 | INFO <class 'event.SetManagerEvent'> binding added for destination myscope, method <function printData at 0x40e63c34> |
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19 | ACCEPTING CONNECTIONS AT: myscope:49152 |
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20 | 11 | Amber Herold | hit enter to kill |
21 | </pre> |
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22 | 1 | Amber Herold | **If the line before last says ACCEPTING CONNECTIONS ...., you have an opened port on this host. |
23 | 11 | Amber Herold | |
24 | # Write down the name of the hose, in this case "myscope", and the opened port, in this case "49152", and proceed to try to connect to that computer from the remote compute in the next step. |
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27 | 6 | Anchi Cheng | h2. Attempt Connection from the Remote Computer |
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30 | 11 | Amber Herold | # remote linux computer> go to the location where Leginon is installed, type the following to find the location: |
31 | 1 | Amber Herold | <pre>start-leginon.py -v</pre> |
32 | 11 | Amber Herold | # remote linux computer> start the 2nd test script with the host name of the microscope computer and its open port |
33 | <pre> |
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34 | remote linux computer/Leginon>test2.py myscope 49152 |
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35 | </pre> |
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36 | 1 | Amber Herold | You should see something like this: |
37 | 11 | Amber Herold | <pre> |
38 | INFO localtransport server created at location {'instance': <localtransport.Server object at 0x2b08e0d43810>} |
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39 | 1 | Amber Herold | INFO tcptransport server created at location {'hostname': 'myremote', 'port': 49152} |
40 | ACCEPTING CONNECTIONS AT: myremote:49152 |
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41 | INFO <class 'event.NodeAvailableEvent'> binding added for destination myremote, method <function printData at 0x2b08e0d51c80> |
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42 | CONNECTING TO: myscope:49154 |
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43 | WARNING localtransport client add failed |
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44 | INFO tcptransport client added |
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45 | 3 | Anchi Cheng | INFO server location set to to {'TCP transport': {'hostname': 'myscope', 'port': 49154}} |
46 | hit enter to kill |
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48 | 1 | Amber Herold | INFO handling threaded |
49 | INFO inserted in queue (class NodeAvailableEvent) |
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50 | INFO <class 'event.NodeAvailableEvent'> handling destination defcon1, method <function printData at 0x2b08e0d51c80> |
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51 | REMOTE CLIENT RESPONDED: myscope:49154 |
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52 | </pre> |
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55 | If you get the last line "REMOTE CLIENT RESPONDED" with correct hostname and port, the |
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56 | connection is fine. You can go to next section to test Leginon run on the remote |
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57 | computer. |
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59 | 17 | Anchi Cheng | You can ignore the following error message print out in test1.py on the microscope PC when you exit it. |
60 | <pre> |
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61 | tcptransport.TransportError: No route to host |
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62 | </pre> |
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63 | 1 | Amber Herold | |
64 | 30 | Anchi Cheng | h2. Array Transport tests |
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66 | There is another pair of tests in leginon: *test1_array_transport.py* and *test2_array_transport.py* that, in addition to the connection test, also send through this connection a few simulated image array. This allows a test of the transfer speed and of the continuing connection. |
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68 | They run in the same way as the above test.py and test2.py. The output is longer. On the window for test1_array_transport.py output, you should find timing of how long it takes to send 32uint 4096x4096 array (=0.5 gigabit), like this: |
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70 | <pre> |
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71 | Event Sent Time (sec) 0.811000108719 |
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72 | </pre> |
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74 | The sent time depends on your network speed. |
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76 | 32 | Anchi Cheng | Prior to that line of timing, it would say that it inserted into queue what it needs to sent etc and the location it is sending to, like this: |
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78 | <pre> |
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79 | INFO inserted in queue <ckass SetManagerEvent> handling threaded |
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80 | INFO leginon.tcptransport client added |
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81 | INFO server location set to {'TCP transport':{'hostname': your_test2_hostname, 'port': the port_test2_opened}} |
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82 | INFO <class 'leginon.event.ArrayPassingEvent'> handling destination anchi3.nimgs.com, method <function printData at 0x103f0eb18> |
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83 | </pre> |
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85 | 30 | Anchi Cheng | On the window for test2_array_transport.py output, you should get, before the line "hit enter to kill": |
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87 | <pre> |
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88 | INFO inserted in queue (class ArrayPassingEvent) |
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89 | INFO handling threaded |
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90 | INFO <class 'leginon.event.ArrayPassingEvent'> handling destination anchi3.nimgs.com, method <function printData at 0x103f0eb18> |
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91 | got array (4096, 4096) |
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92 | </pre> |
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94 | This message will repeat as many times as the number of arrays being sent from test1_array_transport.py |
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96 | If the basic test1.py test2.py pair in the previous section passes but not this. It means that your network connection has trouble keeping the connection alive after each transmission. |
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98 | 1 | Amber Herold | h2. Problem solving tips |
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101 | 15 | Amber Herold | * See Leginon bulletin board thread on "network problem, Leginon not seeing tecnai host":http://emg.nysbc.org/boards/6/topics/3 |
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103 | 29 | Anchi Cheng | h2. Check if the hostname case matches |
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105 | 29 | Anchi Cheng | Python is case-sensitive. We have seen it rejects the host because of it. If using host file to identify the host, it is best to match the case as found from leginon/test1.py |
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107 | h2. Most likely reason for the failure of the test: FIREWALL |
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111 | 7 | Amber Herold | * The easiest solution is have the involving computers inside the same firewall. |
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113 | 23 | Anchi Cheng | * Alternatively, you can |
114 | 25 | Anchi Cheng | # add python to firewall application exception OR |
115 | 26 | Anchi Cheng | # open [[Ports_used_by_Leginon|specific ports for Leginon system]] |
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117 | The latter is described in the Leginon bulletin board thread on "network problem, Leginon not seeing tecnai host":http://emg.nysbc.org/boards/6/topics/3 |
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121 | 27 | Anchi Cheng | h2. Another possible reason for the failure of the test: hostname-ip address mismatch |
122 | 1 | Amber Herold | |
123 | 27 | Anchi Cheng | For leginon to communicate through socket, it needs to know the hostname of itself and the other computer it is connected to in both ways. The hostname also need to map properly to the IP address the partner understand as. |
124 | 1 | Amber Herold | |
125 | 27 | Anchi Cheng | If you are on a dynamically assigned domain name system (DNS), this should all be taken care of. However, since the local hosts file overwrites the DNS assignment, you should check if you have a mismatch if you do have problem. |
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127 | You should therefore check if you have [[add host|added hosts]] to the right files on both sides of the connection. |
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129 | To confirm what python thinks the hosname is on its own computer, run the following in python command line: |
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130 | 1 | Amber Herold | <pre> |
131 | import socket |
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132 | socket.gethostname() |
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133 | 27 | Anchi Cheng | </pre> |
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135 | You can also get the IP address with this python command after importing socket like above |
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136 | <pre> |
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137 | socket.gethostbyname(socket.gethostname()) |
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138 | </pre> |
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140 | You should also check what one computer think the another's ip address is through socket connection once you know the hostname for the other computer |
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141 | <pre> |
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142 | socket.gethostbyname('hostname_of_the_other_computer') |
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143 | 18 | Anchi Cheng | </pre> |
144 | 28 | Anchi Cheng | |
145 | h3. What if the host IP address obtained from socket.gethostbyname on a computer with multiple network card is not the network that connects to other hosts involved in Leginon |
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147 | 33 | Anchi Cheng | h3. Solution 1: *create mapping on the computers that need communication with the needed pairing*. |
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149 | This works if the problem is on your leginon linux box. |
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151 | For example, your leginon linux box has two network connections, one local one toward your scope and camera (192.168.10.30, for example), and one toward your university internet(123.456.78,9). Its hostname "leginonmain.my.u.edu" is default to the university network 123.456.78.9. |
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153 | If there is not a mapping of |
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155 | 192.168.10.30 leginonmain.my.u.edu |
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157 | in the scope/camera Windows 7 computer C:\\WINDOWS\system32\drivers\etc\hosts, the communication will fail. |
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159 | h3. Solution 2: reorder the network connections. We had to do this once. |
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161 | 28 | Anchi Cheng | You may need to [[reorder the network connections]] so that the appropriate network is the first to access. |
162 | 2 | Amber Herold | ______ |
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164 | 21 | Anchi Cheng | [[Test Leginon on the Computer Controlling the Microscope|< Test Leginon on the Computer Controlling the Microscope]] | [[Run Leginon Client on the Instrument Computers|Run Leginon Client on the Instrument Computers >]] |
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166 | ______ |