Conga-Related Settings
Jarvis uses Conga for TCP/IP communications. Jarvis's Conga settings are used to configure the Conga's operation. In most cases Jarvis' default Conga-settings are sufficient. See the Conga User Guide for more detailed information on specific settings. See Jarvis and Conga if your application has other components that also use Conga, such as HttpCommand or isolates, or if you are using Conga that is not located in the Dyalog installation folder.
Once started, Jarvis maintains a reference to to Conga library in the shared LDRC setting. This enables you to manage query and/or manage Conga settings directly if you need to. For instance, j.LDRC.Tree '.' will return the entire Conga object tree.
Jarvis has two shared Conga-related settings - CongaPath and CongaRef.
AcceptFrom
| Description |
AcceptFrom allows you to limit Jarvis incoming connections to a specific set of IP address ranges. AcceptFrom is either one or two character vectors that specify IPV4 and/or IPV6 address ranges. Each vector is a comma-delimited set of IP ranges. |
| Default |
'' |
| Examples |
j.AcceptFrom←'192.168.1.1/127,10.17.221.67/75' |
| Notes |
This setting is documented as AllowEndPoints in the Conga User Guide. Unlike AllowEndPoints, you do not need to specify 'IPV4' or 'IPV6' as Jarvis can automatically determine which IP version is intended. |
BufferSize
| Description |
BufferSize specifies the maximum HTTP headers length that Jarvis will accept. The intent is to block malicious requests that attempt to overwhelm the server by sending huge requests. |
| Default |
10000 |
| Examples |
j.BufferSize←5000 ⍝ allow up to 5000 bytes of HTTP header data |
| Notes |
BufferSize can be used in conjunction with DOSLimit to mitigate Denial of Service (DOS) attacks. |
DenyFrom
| Description |
Similar to AcceptFrom, DenyFrom allows you to deny incoming connections from a specific set of IP address ranges. DenyFrom is either one or two character vectors that specify IPV4 and/or IPV6 address ranges. Each vector is a comma-delimited set of IP ranges. |
| Default |
'' |
| Examples |
j.DenyFrom←'192.168.1.1/127,10.17.221.67/75' |
| Notes |
This setting is documented as DenyEndPoints in the Conga User Guide. Unlike DenyEndPoints, you do not need to specify 'IPV4' or 'IPV6' as Jarvis can automatically determine which IP version is intended. |
DOSLimit
| Description |
To reduce possible Denial Of Service (DOS) attacks, DOSLimit is used to limit the size of HTTP payloads that Jarvis will accept. |
| Default |
¯1 which indicates to use the Conga default value of 10485760 |
| Examples |
j.DOSLimit←100000 ⍝ assumes no message will exceed 100000 bytes |
| Notes |
You should specify a DOSLimit large enough to accept the largest message you anticipate receiving. |
FIFO
| Description |
FIFO controls how Conga will process incoming requests. Setting FIFO to 1 will cause Conga to process requests in a "First In, First Out" order. Setting FIFO to 0 will cause Conga to process requests according to Conga's ReadyStrategy setting. |
| Default |
1 |
| Examples |
j.FIFO←0 ⍝ turn FIFO mode off |
| Notes |
This setting is documented as EnableFifo in the Conga User Guide. |
Port
| Description |
Port is port number that Jarvis will listen on. |
| Default |
8080 |
| Examples |
j.Port←22361 |
| Notes |
Allocating ports below 1024 on Linux typically requires root privileges due to security reasons. |
RootCertDir
| Description |
When running Jarvis over HTTPS, RootCertDir is the path to a folder containing public root certificates. |
| Default |
'' |
| Examples |
Set RootCertDir to the public root certificates folder installed with Dyalog.
dir←1 1⊃1 ⎕NPARTS 2 ⎕NQ '.' 'GetCommandLineArgs'
j.RootCertDir←dir,'PublicCACerts' |
| Notes |
This setting is documented as RootCertDir in the Conga User Guide. See Security for more information. |
Priority
| Description |
Priority is the GnuTLS priority string when using secure communications. Priority specifies the TLS session's handshake algorithms when negotiating a secure connection. |
| Default |
'NORMAL:!CTYPE-OPENPGP' |
| Examples |
j.Priority←'NORMAL:-MD5' ⍝ use the default without HMAC-MD5 |
| Notes |
Setting Priority to something other than the default requires an in-depth understanding of TLS session negotiation. Don't change it unless you know know what you're doing. |
Secure
| Description |
Secure is a Boolean setting that controls whether Jarvis will use TLS. Valid settings are:0 - do not use TLS1 - attempt to use TSL (see notes below)
|
| Default |
0 |
| Examples |
j.Secure←1 ⍝ enable secure communications |
| Notes |
Using TLS requires configuring several settings, see Using TLS. |
ServerCertSKI
| Description |
Under Windows, when using the Microsoft Certificate Store to obtain the server certificate for Jarvis to use, ServerCertSKI is the Server Certificate Subject Key Identifier of the certificate. |
| Default |
'' |
| Examples |
j.ServerCertSKI←'aca7d8f00691129ea0bc3613a00ed8ea9a5e55f5' |
| Notes |
The subject key identifier is a 40 byte hexadecimal string. For more information, see Using TLS. |
ServerCertFile
| Description |
ServerCertFile is the name of the file containing the server's public certificate. |
| Default |
'' |
| Examples |
j.ServerCertFile←'/etc/mycerts/publiccert.pem' |
| Notes |
For more information, see Using TLS. |
ServerKeyFile
| Description |
ServerKeyFile is the name of the file containing the server's private key. |
| Default |
'' |
| Examples |
j.ServerKeyFile←'/etc/mycerts/privatekey.pem' |
| Notes |
Never share your private key file. For more information, see Using TLS. |
ServerName
| Description |
ServerName is the Conga name for the Jarvis server. You can specify the name or have it Conga assign it. |
| Default |
Assigned by Conga in the format 'SRVnnnnnnnn' where nnnnnnnn begins at 00000000 and is incremented when a Jarvis server using the same Conga instance is started. |
| Examples |
)copy conga Conga
j1←Jarvis.New 8080
j2←Jarvis.New 8081
j3←Jarvis.New 8082
j3.ServerName←'MyJarvis'
(j1 j2 j3).Start
(j1 j2 j3).ServerName
SRV00000000 SRV00000001 MyJarvis |
| Notes |
ServerName can be useful when interacting with Conga, particularly when debugging. For example:
j3.(LDRC.Describe ServerName)
0 MyJarvis Server Listen
LDRC is Jarvis's local reference to the Conga library. |
SSLValidation
| Description |
SSLValidation is employed as part of the certificate checking process and is more fully documented in the Conga User Guide. |
| Default |
64 - request but do not require a client certificate |
| Examples |
j.SSLValidation←128 ⍝ require a valid certificate |
| Notes |
For more information, see Using TLS. |
WaitTimeout
| Description |
WaitTimeout is the number of milliseconds that Jarvis will wait in its listening loop before timing out. |
| Default |
15000 - 15 seconds |
| Examples |
j.WaitTimeout←60000 ⍝ wait a minute before timing out |
| Notes |
Conga servers sit in a "wait" loop listening for communications from clients. If no communications occur before WaitTimeout has passed, Conga will signal a "Timeout" event and reiterate the "wait" loop. |