Java EMA Ommconsumer onUpdateMsg function delay 10-20 seconds

hsisupportswd

We are doing migration from JSFC to EMA for consuming HK market real-time data.

We used OmmConsumer to get the data by onUpdateMsg callback function.

The issue happens when the period is during auction close or PM market close.

There is around 30k+ number to update during that period.

You can see the screendump of log that callback of onUpdateMsg is stopped at 16:08:12.

But it is resumed at 16:08:29. There is 27 seconds of delay.

It happens regularly everyday. We also checked that the RTDS server side has no such delayed record.

Could you provide some advice for the coding and troubleshooting?

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hsisupportswd

Typo: 30k+ number of message to update

wasin.w V3

Hello @hsisupportswd

I would like to suggest you enable the EMA XML trace log to check the time that the API receives incoming update messages from the RTDS server. However, I am understanding that checking the log for 30K+ items is too pain.

An application can use the horizontal scaling by creating multiple OMM Consumer instances. You can refer to the Horizontal Scaling example (ex410_MP_HorizontalScaling) in the API package.

You can also refer to the EMA PerfTools in the package which demonstrate best practice and coding for performance.

If the issue still persists after you have applied the method(s) above, I highly recommend you contact the Real-Time APIs Support team to look into the issue. If you are RDC named user, you can go to the https://developers.lseg.com/en/api-catalog/real-time-opnsrc/rt-sdk-java page and click on the "Contact premium support" botton.

hsisupportswd

Thank you for your prompt response.

How can I enable EMA XML trace log?

hsisupportswd

Thank you for your prompt response.

How can I enable EMA XML trace log?

wasin.w V3

Hello @hsisupportswd

The most basic one is XmlTraceToStdout in EmaConfig.xml file. Set it to 1, the API will print all incoming and outgoing messages between the API and Server to standard output or console.

There are lot of options for the XmlTrace configuration available on the EMA Java Configuration Guide document (available in the SDK package)

Jirapongse

@hsisupportswd

I assumed that you are using the API dispatch mode. There are several configurations that relate to this mode.

DispatchTimeoutApiThread: Specifies the duration (in microseconds) for which the internal Enterprise Message API thread is inactive before going active to check whether a message was received. If set to zero, the Enterprise Message API internal thread goes active only if it gets notified about a received message.
MaxDispatchCountApiThread: Specifies the maximum number of messages the Enterprise Message
API dispatches before taking a real-time break

You can change their values via the EMA configuration file (EmaConfig.xml) in the Consumer setting. For more information, please refer to the EMA Configuration guide.

What EMA version are you using?

Otherwise, you can try the user dispatch mode instead. Please refer to the ex130_MP_UserDisp example.

hsisupportswd

Thank you. We will try the XmlTraceToFile first.

hsisupportswd

Hi Jirapongse,

We are using API dispatch mode. Our EMA version is 3.6.1.0.
We tried to remove all code but just left logger.debug.

But the delay still exists. The callback function was idle for 20 seconds. The problem should be on API level.

hsisupportswd

We put the XML parameter to our EMAConfig.xml. But we cannot see the trace file.

Could you advice?

        <Consumer>

            <!-- Name is mandatory  -->

            <Name value="Consumer_1"/>

            <!-- Channel is optional: defaulted to "RSSL_SOCKET + localhost + 14002" -->

            <!-- Channel or ChannelSet may be specified -->

                            <ChannelSet value="Channel_1,Channel_2"/>

            <!-- <WarmStandbyChannelSet value="WarmStandbyChannel_1"/> -->

                    <!--<SessionChannelSet value="Connection_1, Connection_2"/> -->

                    <!--<SessionEnhancedItemRecovery value="1"/>-->

            <!-- Dictionary is optional: defaulted to "ChannelDictionary" -->

            <Dictionary value="Dictionary_2"/>

                    <!--<ReconnectAttemptLimit value="10"/>

                    <ReconnectMinDelay value="2000" />

                    <ReconnectMaxDelay value="6000" />

                    <LoginRequestTimeOut value="5000"/>

                    <RequestTimeout value="5000"/> -->

            <XmlTraceToStdout value="1"/>

            <XmlTraceToFile value="1" />

            <XmlTraceFileName value="/filepath/Ema_trace.xml" />

        </Consumer>

Jirapongse

@hsisupportswd

EMA 3.6.1.L1 was released in 2021.

The latest version is RTSDK Java 2.3.1.L1 aka EMA/ETA 3.9.1.L1 aka 3.9.1.0.

It is better to use the latest version to avoid all known issues.

You can download it from the developer community or Software Download. It is in the Product Family: MDS - API and Products: LSEG Real-Time SDK.

hsisupportswd

Thank you Jirapongse,

Our RTDS server version:

LSEG Real-Time Distribution System 3.8.2.L1 (ssl 80413261b 69)

Is the latest RTSDK version compatible to our server?

Jirapongse

The RTSDK will work with all supported versions of RTDS.

wasin.w V3

Hello

The EMA API version 3.6.1.L1 supports only XmlTraceToStdout configuration.

Please try the latest version (and Dispatch parameters) as my colleague suggestion first.

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