When writing a piece of software, we are in total control of the quality of the product. With integration, many elements are not under our control. Network and firewall are usually managed by IT. With external systems, we usually don’t know how they work, or many times, not given access. Yet, any changes to these elements can cause our interfaces to fail.
For synchronous interfaces, the user would receive instant feedback after each action is taken (e.g. Maximo GIS integration), thus, we don’t usually need to set up alarms. For asynchronous interfaces, which usually run in the background, and don’t give instant feedback, when failure occurs, it usually goes unnoticed. In many cases, we only find out about failures after it has caused some major damage.
A good interface must provide an adequate mechanism to handle failures, and in the case of async integration, proper alarms and reports should be set up so that failures are captured and handled proactively by IT and application administrators.
On the one hand, it is bad to have no monitoring. On the other hand, it is even worse to have too many alarms to the point that people completely ignore everything including the critical issues. This is usually seen in larger organisations. Many readers of this blog probably won’t be surprised when they open the Message Reprocessing app of the Maximo system they manage and find thousands of unprocessed errors in there. It’s likely that those issues have been accumulated and not dealt with for years.
It is hard to create a perfect design from day one and build an interface that works smoothly after the first release. There are many different kinds of problems an external system can throw at us and it is not easy to envision all possible failure modes. As such, we should expect and plan for an intensive monitoring and stabilizing period of a few days to one or two weeks after the first release.
As a rule of thumb, an interface should always be monitored and raise alarms when a failure occurs. It should also provide a mechanism to resubmit/reprocess a failed message. More importantly, there shouldn’t be more than a few alarms raised per day on average from each interface, no matter how critical and high volume the integration is. More than that, it will become too noisy and people will start ignoring those alarms. If an interface raises more than a few alarms a day, there must be some recurring patterns and each of them must be treated as a systemic issue. The software should be rebuilt or updated to handle these recurring issues.
It is easier said than done, and every interface is a continuous learning and improvement process for me. Below are some examples of the interfaces I built or dealt with recently. I hope you find it entertaining to read.
Case #1: Integration of Intelligent Transport System to Maximo
An infrastructure construction company built and is now operating a freeway in Sydney. Maximo is used to manage maintenance activities, mainly on civil infrastructure. Toll point equipment and a traffic monitoring system were provided by an external provider (Kapsch). Device status and maintenance work from this system are exported daily as CSV files and sent to Maximo via SFTP. On the Maximo side, the CSV files are imported using a few automation scripts triggered by a cron task.
The main goal of the interface is to maintain a consolidated database of all assets and maintenance activities in Maximo. It is a non-critical integration because even if it stops working for a day or two, it won’t cause a business disruption. However, occasionally, Kapsch would stop exporting CSV files for various reasons. The problem will only be found out after a while, like when an end-of-month report is produced or when someone tries to look up the status of a certain work order that was not created via the interface. Since we don’t have any access or visibility to the traffic monitoring system managed by Kaspch, we’ll need to build the monitoring and alarms in Maximo.
The difficulty is, when the interface on Kapsch’s side fails, it doesn’t send Maximo anything, there would be no import, and thus no errors or faults seen by Maximo to raise any alarm. The solution we came up with is having a custom logging table in which we write each import as an entry with some basic statistics including import start time, end time, total records processed and the number of records that failed. The statistics are displayed on the Start Center.
For alarm, since this integration is non-critical, an escalation is set to monitor whether there has been no new import within the last 24 hours, Maximo will send out an email to me and the people involved. There are actually a few different interfaces in this integration, such as for device list and preventive maintenance work coming from TrafficCom, or corrective work on faults coming from JIRA. Thus, sometimes, when a system stopped running for various planned or unplanned reasons, I would receive multiple emails for a couple of days in a row, which is too much. So, I tweaked it even further by sending only one email on the first day if one or more interfaces stopped working, and another email reminding me a week later if the issue had not been rectified. After the initial fine-tuning period, the support team on Kapsch and Maximo’s side is added to the recipient list, and after almost two years now, the integration has been running satisfactorily. In other words, there have been a few times files were not received on the Maximo side and the support people involved were always informed and able to take corrective action in a timely manner before the end-users could notice.
Case #2: Integration of CRM and Maximo
A water utility in Queensland uses Maximo for managing infrastructure assets, tracking, and dispatching work to field crews. When a customer calls up requesting a new connection or reporting a problem, the details are entered to a CRM system by the company’s call centre. The request will then be sent to Maximo as a new SR, and then turned into work orders. When the work order is scheduled and a crew has been dispatched, these status updates are sent back to CRM. At any time, if the customer calls up to check on the status of the request, the call centre should be able to provide an answer by looking up the details of the ticket in CRM only. Certain types of problems have high priority such as major leaks or water quality issues. Some issues have SLA with response time in minutes. As such, this integration is highly critical.
WebMethods is used as a middleware to handle this integration, and as part of the steps for sending new SR from CRM to Maximo, the service address will also need to be cross-checked with ArcGIS for verification and standardization. As you can see, there are multiple points of failure with this integration.
This integration was built several years ago and there has been some level of alarms set up in CRM on a few points where there is a high risk of failure such as when a Service Order is created but not picked up by WebMehods or picked up but not sent to Maximo. Despite this, the interface would have some issues every few weeks, and thus, needed to be rebuilt. In addition to existing alarms coming from CRM, several new alarm points were added in Maximo and Webmethods:
- When WM couldn’t talk with CRM to retrieve a new Service Order
- When WM couldn’t send a status update back to CRM
- When WM couldn’t talk to Maximo
- When Maximo couldn’t publish messages to WM
These apply to individual messages coming in and out of Maximo and CRM and any failure would result in an email sent to the developer and the support team.
In the first few days after this new interface was released to Production, the team received a few hundred alarms each day. My capacity to troubleshoot was about a dozen of those alarms a day. Thus, instead of trying to solve them. We tried to identify all recurring patterns of issues and address them by modifying the interface design, and business process, or fixing bad data. A great deal of time was also spent on trying to improve the alarms, such as for each type of issue, detailed error messages, or in many cases, the content of the XML message itself is attached to the email alarm. A new “fix patch” was released to Production about two weeks after the first release, and after that, the integration only produced a few alarms per month. In most cases, the support person can immediately tell what is the cause of the problem by just looking at the email before even logging in to the client’s environment. After almost a year now, all of the possible failure points that we envision, no matter how low of a chance it can occur, have failed and raised alarms at least once, and the support team has always been on top of it. I’m glad that we had put in all of those monitoring in the first place. And as a result, I haven’t heard of any issues that have not been fixed before the end-users become aware of it.
Case #3: Interface with medium criticality/frequency
Of the two examples above, one is low frequency/low criticality; the other is high frequency and highly critical. Most interfaces are somewhere in the middle. Those interfaces that are highly critical but don’t run frequently or don’t need short response time can also be put into this category. In such cases, we might not need to send individual alarms in real time. Although I like to think of myself as pretty good at troubleshooting issues, I don’t think I can handle more than a few issues per day. As such, my rule of thumb is, if I receive more than a few alarms per day, it is too much. As developers, if we don’t think we can handle more than a few alarms a day, I think we shouldn’t do that to the support team (giving them alarms all day long). For the utility company mentioned above, when WebMethods was first deployed, the WM developer configured a bi-daily report that lists all failed transactions that occurred in the last 12 hours. Thus, for most interfaces, we don’t need to set up any specific alarms. If there are a few failures, they will show up in the report and will be looked at by technical support at noon or at the end of the day. This appears to work really well, even for some of the very critical interfaces such as bank transfer orders or invoice payments.
Case #4: Recurring failure resulting in too much alarm
For the integration mentioned in #1 and #2, the key to getting them to work satisfactorily is to spend some time after the first release to monitor the interfaces and fine-tune both the interface itself and the alarms. It is important to have alarms raised when failure occurs, but it is also important to ensure there aren’t too many alarms raised. Not only people will ignore it if they receive too many alarms, it also makes it hard to tell the critical issues apart from other noisy, less important ones. From my experience, dealing with those noisy alarms is usually quite easy. Most of the time, the alarms come from a few recurring failures that are ignored. When people first look at it, they can easily be overwhelmed by the high number of issues they see initially, and thus, feel reluctant to deal with it. In many cases, I simply deal with each alarm/failure one by one, and carefully document the error message or symptom, and the solution for each problem on an Excel spreadsheet. Usually, after a few I’ve gone through a few issues, they would all come back to some recurring patterns that can easily be dealt with.
Example: a water utility uses an external asset register system, and the asset data is synchronized to Maximo in a near real-time frequency. The interface produces almost 1GB of SystemOut.log file each day causing the logging system to become useless. I looked at each error and documented them one by one. After about two hours, it was clear that 80% of the errors came from missing locations which were not synchronized. When the integration tries to create new assets under these locations, it will write a bunch of errors to SystemOut.log. I did a quick scan and wrote down all of the missing locations and quickly added them to Maximo using MXLoader. After that, the amount of error was greatly reduced. By doing occasional checks on the log files in the following few days, I was able to list all of the missing 30+ locations and able to remove all of the related errors. The remaining errors found in the log files were easily handled separately. Some critical issues only came under the radar of the business after that.
