1 00:00:00,640 --> 00:00:03,990 So what are PowerShell jobs? Well a 2 00:00:03,990 --> 00:00:06,930 PowerShell job is a background job that 3 00:00:06,930 --> 00:00:10,260 runs a command without interacting with 4 00:00:10,260 --> 00:00:12,810 that specific session. While that's 5 00:00:12,810 --> 00:00:14,940 running, you can continue to work in the 6 00:00:14,940 --> 00:00:17,590 same PowerShell session without 7 00:00:17,590 --> 00:00:20,330 interruption while the job runs in the 8 00:00:20,330 --> 00:00:24,460 background. There were two different types 9 00:00:24,460 --> 00:00:26,610 of PowerShell jobs that can be ran. The 10 00:00:26,610 --> 00:00:28,380 first is the default, which is a 11 00:00:28,380 --> 00:00:31,320 PowerShell 7 version of that. We simply 12 00:00:31,320 --> 00:00:34,010 just say start job, and it initiates that 13 00:00:34,010 --> 00:00:36,740 job. We can also run a backwards 14 00:00:36,740 --> 00:00:39,100 compatibility version of that, which is 15 00:00:39,100 --> 00:00:42,870 PowerShell 5.1. Now to execute these types 16 00:00:42,870 --> 00:00:44,950 of jobs, let's say that we first wanted to 17 00:00:44,950 --> 00:00:46,930 retrieve the version of the PowerShell 18 00:00:46,930 --> 00:00:49,250 that we have. So to do this, we'll use 19 00:00:49,250 --> 00:00:52,310 PSVersionTable and then get the PSVersion 20 00:00:52,310 --> 00:00:56,160 property from the response. If I wanted to 21 00:00:56,160 --> 00:00:59,840 execute this using PowerShell version 5.1, 22 00:00:59,840 --> 00:01:03,400 I would call Start‑Job. ScriptBlock is the 23 00:01:03,400 --> 00:01:06,200 property or at least the parameter that we 24 00:01:06,200 --> 00:01:09,700 use to pass in specific syntax we wish to 25 00:01:09,700 --> 00:01:11,370 execute. So we're going to call the 26 00:01:11,370 --> 00:01:13,530 PSVersion. And then there's a property 27 00:01:13,530 --> 00:01:16,960 called PSVersion, and I can pass in 5.1, 28 00:01:16,960 --> 00:01:21,770 7.0, etc. So we can specifically tell this 29 00:01:21,770 --> 00:01:26,230 command to run using 5.1. Then, of course, 30 00:01:26,230 --> 00:01:28,120 if I want to execute in the native 31 00:01:28,120 --> 00:01:30,760 PowerShell 7, I don't need to pass the 32 00:01:30,760 --> 00:01:34,850 PSVersion. I can say Start‑Job ScriptBlock 33 00:01:34,850 --> 00:01:36,620 and then pass in the code that we wish to 34 00:01:36,620 --> 00:01:39,500 execute. So this just provides us a way of 35 00:01:39,500 --> 00:01:41,770 backwards compatibility. For example, you 36 00:01:41,770 --> 00:01:44,060 may have scripts that don't support some 37 00:01:44,060 --> 00:01:46,300 of the features in PowerShell 7. or you 38 00:01:46,300 --> 00:01:48,800 may have something that uses a method that 39 00:01:48,800 --> 00:01:51,410 doesn't exist in PowerShell 7 anymore. So 40 00:01:51,410 --> 00:01:53,660 we can at least backwards compat that 41 00:01:53,660 --> 00:01:57,140 PowerShell script that we execute. There 42 00:01:57,140 --> 00:01:59,710 are two core PowerShell job types. The 43 00:01:59,710 --> 00:02:02,140 first one is a background job. This is 44 00:02:02,140 --> 00:02:04,400 only available within the current 45 00:02:04,400 --> 00:02:06,720 PowerShell session. So what I mean by that 46 00:02:06,720 --> 00:02:09,200 is when you launch the PowerShell window, 47 00:02:09,200 --> 00:02:12,030 initiate Start‑Job, you can retrieve 48 00:02:12,030 --> 00:02:14,580 information about that job within that 49 00:02:14,580 --> 00:02:17,460 same window. If I was to launch a new 50 00:02:17,460 --> 00:02:20,650 PowerShell window, I have no access to 51 00:02:20,650 --> 00:02:23,030 that existing background job because it 52 00:02:23,030 --> 00:02:25,830 doesn't exist in the same session. The 53 00:02:25,830 --> 00:02:27,110 second option that we're not going to 54 00:02:27,110 --> 00:02:30,210 speak about at all during this course is 55 00:02:30,210 --> 00:02:32,560 scheduled jobs. This was a process that we 56 00:02:32,560 --> 00:02:34,930 could utilize in previous versions of 57 00:02:34,930 --> 00:02:37,800 PowerShell where this creates a scheduled 58 00:02:37,800 --> 00:02:40,380 background job that's independent of the 59 00:02:40,380 --> 00:02:42,950 current PowerShell session. So that means 60 00:02:42,950 --> 00:02:44,950 the same example is before, I kick off 61 00:02:44,950 --> 00:02:47,240 something in one PowerShell window, I can 62 00:02:47,240 --> 00:02:49,360 open the second PowerShell window, and I 63 00:02:49,360 --> 00:02:53,450 can communicate between the two. Now if we 64 00:02:53,450 --> 00:02:55,520 look at the job types, they're broken down 65 00:02:55,520 --> 00:02:58,060 even further. So the first one we've 66 00:02:58,060 --> 00:03:00,230 talked about is the background job. This 67 00:03:00,230 --> 00:03:02,930 is how you initiate it by using Start‑Job 68 00:03:02,930 --> 00:03:05,340 cmdlet, and that will create whatever 69 00:03:05,340 --> 00:03:08,040 script block or task that you've created 70 00:03:08,040 --> 00:03:11,150 and push it to a background job. The other 71 00:03:11,150 --> 00:03:12,780 one is what's referred to was a remote 72 00:03:12,780 --> 00:03:15,280 job. So this means I can use what's called 73 00:03:15,280 --> 00:03:18,740 Invoke‑Command, which says invoke this 74 00:03:18,740 --> 00:03:20,900 specific thing, whether it's another 75 00:03:20,900 --> 00:03:23,110 PowerShell script or a command. And then I 76 00:03:23,110 --> 00:03:27,110 use a property called AsJob. When I use 77 00:03:27,110 --> 00:03:30,180 ‑AsJob, it pushes that to become a 78 00:03:30,180 --> 00:03:32,560 background job. So you'll utilize this, 79 00:03:32,560 --> 00:03:34,780 for example, if we're trying to execute 80 00:03:34,780 --> 00:03:37,030 commands on remote servers or 81 00:03:37,030 --> 00:03:39,190 workstations, and you wanted to run it as 82 00:03:39,190 --> 00:03:42,520 a job. We then have what's called a 83 00:03:42,520 --> 00:03:45,900 PSWorkflowJob. So this is started again by 84 00:03:45,900 --> 00:03:49,520 using the AsJob parameter of a specific 85 00:03:49,520 --> 00:03:52,890 PowerShell workflow job. We also then have 86 00:03:52,890 --> 00:03:56,290 CIMJobs and WMIJobs, which also can take 87 00:03:56,290 --> 00:03:59,030 the AsJob parameter, and that gets bundled 88 00:03:59,030 --> 00:04:02,580 into the CD XML or the WMI modules that 89 00:04:02,580 --> 00:04:04,960 might be utilized. We then also have 90 00:04:04,960 --> 00:04:07,920 PSEventJobs, and this is where you can use 91 00:04:07,920 --> 00:04:11,380 Register‑ObjectEvent, and then you add an 92 00:04:11,380 --> 00:04:13,920 action parameter. An event job, for 93 00:04:13,920 --> 00:04:15,460 example, can be used when you kick 94 00:04:15,460 --> 00:04:17,890 something off. I want an event to happen, 95 00:04:17,890 --> 00:04:20,420 and then I want this to happen too. So 96 00:04:20,420 --> 00:04:23,000 those are the different types of PowerShell jobs that we have.