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1 -Volume Mapping (On-premise)
1 +novice-file-based-connectivity-processing-a-file-per-line
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1 1  {{container}}{{container layoutStyle="columns"}}(((
2 -When you need to read and write files from an on-premise disk, you need to know the path in which the data is stored and make sure that the docker container in your runtime(s) running has access to this path. There are several ways of dealing with this challenge. First, this microlearning will discuss the various alternatives and best approaches in these scenarios.
2 +In this microlearning, we will learn how you can define a header line in which you specify the naming of the various columns. Some external systems require a header line when you supply them with data via a flat file that is placed somewhere.
3 3  
4 4  Should you have any questions, please contact [[academy@emagiz.com>>mailto:academy@emagiz.com]].
5 5  
6 +* Last update: May 28th, 2021
7 +* Required reading time: 5 minutes
8 +
6 6  == 1. Prerequisites ==
7 7  
8 8  * Basic knowledge of the eMagiz platform
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9 9  
10 10  == 2. Key concepts ==
11 11  
12 -This microlearning centers around learning how to set up your volume mapping correctly so you can exchange file-based data on-premise.
15 +This microlearning centers around learning how to place a header line on a flat-file output.
13 13  
14 -By volume mapping, we mean: Creating a configuration through which the docker container can read and write data on a specific path on an on-premise machine.
17 +By header line we mean: A line in the output that defines the naming of the various columns
15 15  
16 -There are several options for volume mapping for your on-premise machine.
17 -* Volume
18 -* Bind mount
19 -* Temporary file system
20 -* Named pipe
19 +Some external parties require that the first line in the flat file output (i.e. CSV) is filled with column names (i.e. headers). In eMagiz, we call this line a header line.
21 21  
22 -== 3. Volume Mapping (On-premise) ==
21 +== 3. Header line ==
23 23  
24 -When you need to read and write files from an on-premise disk, you need to know the path in which the data is stored and make sure that the docker container in your runtime(s) running has access to this path. There are several ways of dealing with this challenge. First, this microlearning will discuss the various alternatives and best approaches in these scenarios.
23 +In this microlearning, we will learn how you can define a header line in which you specify the naming of the various columns. Some external systems require a header line when you supply them with data via a flat file that is placed somewhere. The header line is the first line in the flat file output. Within this line, the various column names are specified for clarity.
25 25  
26 -There are several options for volume mapping for your on-premise machine.
27 -* Volume
28 -* Bind mount
29 -* Temporary file system
30 -* Named pipe
25 +To add such a header line in eMagiz you need to navigate to the Create phase of eMagiz and open the exit flow in which you want to drop the file to a certain location. Within the context of this flow, we need to add functionality that will ensure that a header line is written to the output before any functional lines are added. To do so first enter "Start Editing" mode on flow level. After you have done so please add a file outbound channel adapter to the flow including an input channel. We will use this component to write our header line to the flat file output.
31 31  
32 -Below we will explain the differences between the various options available for your volume mapping. But before we do, we first explain how to set up this configuration within eMagiz. Then, you must navigate to Deploy -> Architecture on the model level. In this overview, you can access the Volume mapping per runtime deployed on-premise. To do so, you can right-click on the runtime to access the context menu.
27 +Ensure that the directory to which you reference is the same as in your functional file outbound channel adapter.
33 33  
34 -[[image:Main.Images.Microlearning.WebHome@novice-file-based-connectivity-volume-mapping-on-premise--volume-option-context-menu.png]]
29 +[[image:Main.Images.Microlearning.WebHome@novice-file-based-connectivity-header-line--file-outbound-channel-header-line.png]]
35 35  
36 -When you click this option, you will see the following pop-up. In this pop-up, you can define the machine-level and runtime-level volumes. More on that later. This is the starting point for configuring your volume mapping. We will walk through each available option and explain how they work and should be configured.
31 +Now it is time to turn our attention to the Advanced tab. For the Mode select Ignore. Select this option to ensure that the header line is only written down once when there is no output created yet and not somewhere in the middle, in the end, or every time. Furthermore, select the option Append New Line to ensure that the remainder of the information is not appended to the same line.
37 37  
38 -[[image:Main.Images.Microlearning.WebHome@novice-file-based-connectivity-volume-mapping-on-premise--volume-mapping-pop-up.png]]
33 +[[image:Main.Images.Microlearning.WebHome@novice-file-based-connectivity-header-line--file-outbound-channel-header-line-advanced.png]]
39 39  
40 -{{info}}Note that you should be in "Start editing" mode to make any changes to the configuration of your volume mapping.
35 +After you have done so we need to add a standard transformer that defines the various column names to be written to the flat file output. To do so add the standard transformer component to the canvas including an input channel. After you have done so define the relevant SpEL expression. In this case, we advise using a property value that represents a string of column names. The value of the property should be something as follows:
41 41  
42 -=== 3.1 Volume ===
37 +'Header1;Header2;Header3;Header4'
43 43  
44 -To make this work in eMagiz you need to navigate to the Create phase of eMagiz and open the entry flow in which you want to archive the files. Within the context of this flow, we need to add functionality that will ensure that each input file is archived and cleaned up when older than three days. To do so first enter "Start Editing" mode on flow level. The first decision we have to take is how we are going to name the files within the archiving. The best practice, in this case, is the original filename + the current time as a suffix. You can define this by dragging a format file name generator (support object) to the canvas.
39 +Do note that the separator, in this case, needs to match the requirements of the external system. At the flow configuration level, the standard transformer should look as follows.
45 45  
46 -[[image:Main.Images.Microlearning.WebHome@novice-file-based-connectivity-archiving--file-name-generator.png]]
41 +[[image:Main.Images.Microlearning.WebHome@novice-file-based-connectivity-header-line--define-columns-names.png]]
47 47  
48 -After we have done this please add a file outbound channel adapter to the flow including an input channel. Ensure that you use a property for the directory that references another directory compared to the input directory to prevent creating an infinite loop.
43 +Our last step is to ensure that this piece of logic is tied to the main flow and is executed before writing the functional line(s) to the output file. To make that happen we need to add a wiretap to the flow. With the help of this functionality, you can define which part of the logic takes precedence over another part of the logic. To do so double click on the channel on which you want to place a wiretap, select the option wiretap and select the correct wiretap channel. After you have done this the result should be something as follows:
49 49  
50 -[[image:Main.Images.Microlearning.WebHome@novice-file-based-connectivity-archiving--archiving-config-file-outbound-basic.png]]
45 +[[image:Main.Images.Microlearning.WebHome@novice-file-based-connectivity-header-line--wiretap-result.png]]
51 51  
52 -Now that we have configured the basics let us turn our attention to the advanced configuration. In the advanced tab of this component, we need to select the file name generator to ensure that the files are named correctly. In case you process each line separately you have to choose whether to save them as separate files in the archive or by appending them again. This can be achieved by selecting the correct Mode. In most cases, however, the default Mode of Replace will suffice.
47 +With these couple of steps, you have now successfully added logic to your flow that will ensure that a header line is added before any functional line(s) are written to the output file.
53 53  
54 -[[image:Main.Images.Microlearning.WebHome@novice-file-based-connectivity-archiving--archiving-config-file-outbound-advanced.png]]
55 -
56 -The moment you are satisfied press Save. Now that we have configured this it becomes time to determine how we get the needed input to write to our archive. In the example we are using here we want to archive our input file so we need to ensure that the data we received is written to the archive as soon as possible. To do so place a wiretap on the first channel after retrieving the file. This will make sure that the message is archived before processed further. The result should be something as shown below. Note that this same piece of logic could be applied in other flows within the eMagiz platform in a similar manner.
57 -
58 -[[image:Main.Images.Microlearning.WebHome@novice-file-based-connectivity-archiving--archiving-result.png]]
59 -
60 -=== 3.2 Clean up the Archive ===
61 -
62 -To ensure that the data is not kept indefinitely we need to clean up the archive. We do so to prevent problems with disk space but also to prevent data leaks of old data that could impact the privacy of others. Before we can set up the logic in eMagiz we need to talk to the customer to see what an acceptable term is within which the data is kept. In most cases, this is a week or two weeks. In this example, we have chosen three days.
63 -
64 -Now that we know the limit it is time to configure the components. We start with a composite file filter (support object). Within this filter, we at least define how old a file must be before it can be deleted (in milliseconds). If we turn three days into milliseconds we get 259200000. Furthermore, we at least define that we only want to delete regular files.
65 -
66 -[[image:Main.Images.Microlearning.WebHome@novice-file-based-connectivity-archiving--file-list-filter-for-archive-cleanup.png]]
67 -
68 -Having done so we can add a file inbound channel adapter to the canvas including an output channel. Ensure that the property reference for the directory matches the one you have used before in the outbound channel adapter. Furthermore link the filter to the component and define the poller according to the best practice.
69 -
70 -[[image:Main.Images.Microlearning.WebHome@novice-file-based-connectivity-archiving--file-inbound-archive-cleanup.png]]
71 -
72 -One thing we should not forget within this configuration is to set the Max messages per poll on the Advanced tab of the poller-configuration to a sufficiently high number (i.e. 50). If you forget to do so and you only check once a day it will mean that only one message will be deleted that day.
73 -
74 -[[image:Main.Images.Microlearning.WebHome@novice-file-based-connectivity-archiving--file-inbound-archive-cleanup-max-messages-per-poll.png]]
75 -
76 -Now eMagiz will check on a set time interval whether there are files that are older than three days that are ready for deletion. One last step to go. This last step will ensure that all files that fit the bill will be deleted from the archive. Simply add a standard service activator to the canvas and define the following SPeL expression within the component: payload.delete().
77 -
78 -[[image:Main.Images.Microlearning.WebHome@novice-file-based-connectivity-archiving--archive-cleanup-deletion.png]]
79 -
80 -This will ensure that each file that is retrieved will indeed be deleted from the archive.
81 -
82 82  == 4. Assignment ==
83 83  
84 -Configure an entry in which you build the archiving and the clean up of the archiving.
51 +Configure an exit in which you define and write a header line to a flat-file output before adding functional lines.
85 85  This assignment can be completed with the help of the (Academy) project that you have created/used in the previous assignment.
86 86  
87 87  == 5. Key takeaways ==
88 88  
89 -* Archiving is used for audit purposes
90 -* Archiving is used for retry scenarios
91 -* Ensure that data is cleaned after a retention period to keep in control of the data
92 -* Don't forget the max messages per poll
56 +* The header line contains the names of the columns of the flat file output
57 +* Use the Ignore mode to ensure the header line is created once
58 +* Use the wiretap to ensure the header line is created first
93 93  
94 94  == 6. Suggested Additional Readings ==
95 95  
96 -If you are interested in this topic and want more information on it please read the help text provided by eMagiz and check out the following store content:
62 +There are no suggested additional readings on this topic
97 97  
98 -* [[File Archiving>>doc:Main.eMagiz Store.Accelerators.File Archiving.WebHome||target="blank"]]
99 -* [[Delete Folder(s)>>doc:Main.eMagiz Store.Accelerators.Delete Folder(s).WebHome||target="blank"]]
100 -
101 101  == 7. Silent demonstration video ==
102 102  
103 103  This video demonstrates how you could have handled the assignment and gives you some context on what you have just learned.
104 104  
105 -{{video attachment="novice-file-based-connectivity-characterset.mp4" reference="Main.Videos.Microlearning.WebHome"/}}
68 +{{video attachment="novice-file-based-connectivity-header-line.mp4" reference="Main.Videos.Microlearning.WebHome"/}}
106 106  
107 107  )))((({{toc/}}))){{/container}}{{/container}}