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Delphix

Exercising Name Resolution with Delphix Network Latency Test (KBA5306)

 

KBA

KBA# 5306

 

Issue

SnapSync, VDB provision, or Environment creation may fail if the Delphix Engine encounters an issue resolving a hostname or fully qualified domain name (FQDN).  This typically indicates a problem with the configured DNS server (or possibly a simple typo of the host address). In these instances, it can be useful to manually exercise name resolution and provide additional detail to the network admin team.

As the Delphix Engine CLI and GUI do not provide all standard network diagnostic tools (such as traceroute, nslookup), the CLI Network Latency Test can be used to quickly validate name resolution on-demand.

Please note, this method does not provide the same options to query a specific DNS server, or detail the server IP responding as nslookup does from another OS, but can be used as one step in troubleshooting.

Applicable Delphix Versions

Click here to view the versions of the Delphix engine to which this article applies
Major Release All Sub Releases
6.0 6.0.0.0, 6.0.1.0, 6.0.1.1, 6.0.2.0

5.3

5.3.0.0, 5.3.0.1, 5.3.0.2, 5.3.0.3, 5.3.1.0, 5.3.1.1, 5.3.1.2, 5.3.2.0, 5.3.3.0, 5.3.3.1, 5.3.4.0, 5.3.5.0 5.3.6.0, 5.3.7.0, 5.3.7.1, 5.3.8.0, 5.3.8.1, 5.3.9.0

5.2

5.2.2.0, 5.2.2.1, 5.2.3.0, 5.2.4.0, 5.2.5.0, 5.2.5.1, 5.2.6.0, 5.2.6.1

5.1

5.1.0.0, 5.1.1.0, 5.1.2.0, 5.1.3.0, 5.1.4.0, 5.1.5.0, 5.1.5.1, 5.1.6.0, 5.1.7.0, 5.1.8.0, 5.1.8.1, 5.1.9.0, 5.1.10.0

5.0

5.0.1.0, 5.0.1.1, 5.0.2.0, 5.0.2.1, 5.0.2.2, 5.0.2.3, 5.0.3.0, 5.0.3.1, 5.0.4.0, 5.0.4.1 ,5.0.5.0, 5.0.5.1, 5.0.5.2, 5.0.5.3, 5.0.5.4

4.3

4.3.1.0, 4.3.2.0, 4.3.2.1, 4.3.3.0, 4.3.4.0, 4.3.4.1, 4.3.5.0

4.2

4.2.0.0, 4.2.0.3, 4.2.1.0, 4.2.1.1, 4.2.2.0, 4.2.2.1, 4.2.3.0, 4.2.4.0 , 4.2.5.0, 4.2.5.1

4.1

4.1.0.0, 4.1.2.0, 4.1.3.0, 4.1.3.1, 4.1.3.2, 4.1.4.0, 4.1.5.0, 4.1.6.0

Instruction

The Delphix Admin GUI interface for Network Latency test only provides the ability to select an existing Environment.  To utilize the network latency test via CLI, ssh to the Engine with any Delphix Admin account, and navigate to /network test latency.

delphixEngine> network test latency
delphixEngine network test latency> create

Create a new network test, and set the remoteAddress parameter to the hostname or FQDN you wish to check name resolution.  Note, in this interface both remoteAddress and remoteHost are available... the remoteHost parameter only accepts an existing Environment name, so remoteAddress allows any entry.

If the hostname or FQDN can be resolved, the latency test will start and complete successfully.  If the hostname or FQDN cannot be resolved, an error will be received indicating the entry is not a valid hostname or IP address.  Examples of a successful and a failed test are provided below to illustrate.

delphixEngine network test latency create *> set remoteAddress=delphixEngine.delphix.com
delphixEngine network test latency create *> commit
    `NETWORK_LATENCY_TEST-1
    Dispatched job JOB-217
    NETWORK_LATENCY_TEST_EXECUTE job started for "delphixEngine.delphix.com-2019-12-06T17:34:45.256Z".
    Executing network latency test.
    NETWORK_LATENCY_TEST_EXECUTE job for "delphixEngine.delphix.com-2019-12-06T17:34:45.256Z" completed successfully.
delphixEngine network test latency> create
delphixEngine network test latency create *> set remoteAddress=notindns.delphix.com
delphixEngine network test latency create *> commit
   Error: "notindns.delphix.com" is not a valid hostname or IP address.
  Action: Make sure that any hostname provided resolves to a valid IP address and that the Delphix Engine's DNS configuration is correct.

Further, a test that completes successfully can be reviewed to check the IP address resolved via DNS, by reviewing the details of the test.  In the example below, the test named "examplehost.co-2020-05-20T22:02:38.184Z" that completed successfully is reviewed.  The remoteAddress parameter displays the IP address used for the test to complete.

Please note this does not provide a comprehensive method to view multiple IP addresses resolved by a host name or FQDN.

delphixEngine network test latency> ls
Objects
NAME                                             STATE      AVERAGE  
examplehost.co-2020-05-20T22:02:38.184Z  COMPLETED  20112usec


Operations
create
delphixEngine network test latency> select examplehost.co-2020-05-20T22:02:38.184Z 
delphixEngine network test latency 'examplehost.co-2020-05-20T22:02:38.184Z'> ls
Properties
    type: NetworkLatencyTest
    name: examplehost.co-2020-05-20T22:02:38.184Z
    average: 20112usec
    endTime: 2020-05-20T22:03:14.905Z
    loss: 0
    maximum: 20558usec
    minimum: 19789usec
    parameters:
        type: NetworkLatencyTestParameters
        remoteAddress: seanora19src.dlpxdc.co
        remoteHost: seanora19src.dlpxdc.co
        requestCount: 20
        requestSize: 16B
    reference: NETWORK_LATENCY_TEST-1
    remoteAddress: 10.110.205.117
    startTime: 2020-05-20T22:02:38.184Z
    state: COMPLETED
    stddev: 323usec

DNS server configuration details are not accessible through the Delphix Admin interfaces; as this is a system configuration parameter, only the System Setup interface provides these configuration details.

clipboard_e63756d602ad22f6b09929cefe080f992.png

delphixEngine> network
delphixEngine network> setup
delphixEngine network setup> ls
Properties
    defaultRoute: <redacted gateway>
    dhcp: true
    dnsDomain: delphix.com
    dnsServers: <redacted server1>,<redacted DNS server2>
    hostname: delphixEngine
    primaryAddress: <redacted address>/19

Any changes to the DNS server configuration can also be completed through GUI or CLI (Only possible if static interface is configured, ie DHCP:false)