Commit Graph

15 Commits (9f5f4ba729386c2e71b841c327ae06fc0cea4b8b)

Author SHA1 Message Date
Anthony Yeh be1fe95534 CronJob: Use PATCH to adopt Jobs. 2017-04-19 15:42:34 -07:00
Anthony Yeh e085f1f83c CronJob: Apply missing ControllerRefs to Jobs created by a CronJob.
This should only happen if the Jobs were created by an older version
of the CronJob controller, since from now on we add ControllerRef upon
creation.

CronJob doesn't do actual adoption because it doesn't use label
selectors to find its Jobs. However, we should apply ControllerRef
for potential server-side cascading deletion, and to advise other
controllers we own these objects.
2017-04-18 14:00:18 -07:00
xujun e626e45b4d Remove unused argument of 'groupJobsByParent' function in cronjob controller. 2017-03-20 12:43:10 -04:00
Maciej Szulik 7cba9d9c92 Issue 37166: remove everything from batch/v2alpha1 that is not new 2017-03-06 12:12:38 +01:00
Clayton Coleman 469df12038
refactor: move ListOptions references to metav1 2017-01-23 17:52:46 -05:00
Clayton Coleman 9a2a50cda7
refactor: use metav1.ObjectMeta in other types 2017-01-17 16:17:19 -05:00
Kubernetes Submit Queue 9d2fce7c22 Merge pull request #39608 from peay/cronjob-too-many-times-to-list
Automatic merge from submit-queue

Do not list CronJob unmet starting times beyond deadline

**What this PR does / why we need it**:

See #36311. `getRecentUnmetScheduleTimes` gives up after 100 unmet times to avoid wasting too much CPU or memory generating all the times, as it generates them sequentially.

When concurrency is forbidden, this is conceptually un-necessary: we only need the last unmet start time. This suggests that when concurrency is forbidden, we could generate times by going backward in time from now. This is not very practical as CronJob currently relies on a package that only provides `Next` and no `Prev`. Hand-cooking a `Prev` does not seem like a good idea. I could submit a PR to the cron library to add a `Prev` method, and use that when concurrency is forbidden through something like `getLastUnmetScheduleTime`. This would be `O(1)` and there would be no limit involved.

(edit: actually, even for the other concurrency settings, we only start the last unmet start times -- there is a `TODO` in the controller to actually start all of them, but that is not implemented at the moment. This means the solution would apply, at least temporarily, to all concurrency settings).

cc @soltysh what do you think?

In the meantime, I would suggest to do something simple. Currently, the user has no way to configure anything to ensure that his CronJob will not get stuck if one job takes more that 100 unmet times.

 `getRecentUnmetScheduleTimes` starts with an initial time corresponding to the last start (or to the creation of the CronJob, if nothing has started yet). However, when `StartingDeadlineSeconds` is set, the controller will not start anything that is older than the deadline, so if the last start is way beyond the deadline, we are generating potentially lots of unmet start times that will not be considered by the scheduler for scheduling anyway.

Consider a job running every minute, where the last instance has taken 120 minutes. This means there are more than 100 unmet times when we start counting from the last start time.

**The PR makes `getRecentUnmetScheduleTimes` only consider times that do not fall beyond the deadline.** Here, the CronJob can be configured with a `StartingDeadlineSeconds` of, say, 10 minutes. After the 120min job has run, `getRecentUnmetScheduleTimes` will only consider the times in the last 10 minutes from now, and will not get stuck.

As a side note on the max. number of unmet times to use as limits in terms of CPU used by the controller: I have run a quick benchmark on my i7 mac. Schedules corresponding to "once a week" tend to be more expensive to generate unmet times for. Just FYI.

```
+--------------+---------------+--------------+
|   SCHEDULE   | MISSED STARTS |    TIMING    |
+--------------+---------------+--------------+
| */1 * * * ?  |           100 | 383.645µs    |
| */30 * * * ? |           100 | 354.765µs    |
| 30 1 * * ?   |           100 | 1.065124ms   |
| 30 1 * * 0   |           100 | 1.80034ms    |
| */1 * * * ?  |           500 | 1.341365ms   |
| */30 * * * ? |           500 | 1.814441ms   |
| 30 1 * * ?   |           500 | 8.475012ms   |
| 30 1 * * 0   |           500 | 10.020613ms  |
| */1 * * * ?  |          1000 | 2.551697ms   |
| */30 * * * ? |          1000 | 4.075813ms   |
| 30 1 * * ?   |          1000 | 17.674945ms  |
| 30 1 * * 0   |          1000 | 19.149324ms  |
| */1 * * * ?  |         10000 | 25.725531ms  |
| */30 * * * ? |         10000 | 87.520022ms  |
| 30 1 * * ?   |         10000 | 174.29216ms  |
| 30 1 * * 0   |         10000 | 196.565748ms |
+--------------+---------------+--------------+
```

using

```.go
package main

import (
    "fmt"
    "time"
    "os"
    "strconv"

    "github.com/robfig/cron"
    "github.com/olekukonko/tablewriter"
)

func timeSchedule(schedule string, iterations int) (time.Duration) {
    sched, err := cron.ParseStandard(schedule)

    if err != nil {
        panic(fmt.Sprintf("Unparseable schedule: %s", err))
    }

    start := time.Now()
    t := time.Now()

    for i := 1; i <= iterations; i++ {
        t = sched.Next(t)
    }

    return time.Since(start)
}

func main() {
    table := tablewriter.NewWriter(os.Stdout)
    table.SetHeader([]string{"Schedule", "Missed starts", "Timing"})

    schedules := []string{"*/1 * * * ?", "*/30 * * * ?", "30 1 * * ?", "30 1 * * 0"}
    iteration_nums := []int{100, 500, 1000, 10000}

    for _, iterations := range iteration_nums {
        for _, schedule := range schedules {
            table.Append([]string{schedule,
                                  strconv.Itoa(iterations),
                                  timeSchedule(schedule, iterations).String()})
        }
    }
    table.Render()
}
```

**Which issue this PR fixes**: fixes #36311

**Special notes for your reviewer**:

**Release note**:

```release-note
```
2017-01-17 00:41:45 -08:00
peay d141a43d86 Do not list CronJob unmet starting times beyond deadline 2017-01-15 12:29:20 -05:00
deads2k 6a4d5cd7cc start the apimachinery repo 2017-01-11 09:09:48 -05:00
NickrenREN 639572ac68 fix redundant alias and remove unused function 2017-01-09 17:13:09 +08:00
Maciej Szulik 9f064c57ce Remove extensions/v1beta1 Job 2016-12-17 00:07:24 +01:00
Clayton Coleman 3454a8d52c
refactor: update bazel, codec, and gofmt 2016-12-03 19:10:53 -05:00
Clayton Coleman 5df8cc39c9
refactor: generated 2016-12-03 19:10:46 -05:00
Chao Xu 7eeb71f698 cmd/kube-controller-manager 2016-11-23 15:53:09 -08:00
Maciej Szulik 41d88d30dd Rename ScheduledJob to CronJob 2016-11-07 10:14:12 +01:00