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[APM] Clock skew fix #3

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merged 1 commit into from
Oct 30, 2018
Merged

[APM] Clock skew fix #3

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2 changes: 1 addition & 1 deletion ...ponents/app/TransactionDetails/Transaction/WaterfallContainer/Waterfall/WaterfallItem.tsx
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Original file line number Diff line number Diff line change
Expand Up @@ -116,7 +116,7 @@ export function WaterfallItem({
}

const width = (item.duration / totalDuration) * 100;
const left = (item.offset / totalDuration) * 100;
const left = ((item.offset + item.skew) / totalDuration) * 100;
const Label = item.docType === 'transaction' ? TransactionLabel : SpanLabel;

return (
Expand Down
5 changes: 5 additions & 0 deletions ...terfallContainer/Waterfall/waterfall_helpers/__snapshots__/waterfall_helpers.test.ts.snap
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Original file line number Diff line number Diff line change
Expand Up @@ -13,6 +13,7 @@ Array [
"name": "APIRestController#products",
"offset": 0,
"serviceName": "opbeans-java",
"skew": 0,
"timestamp": 1536763736366000,
"transaction": Object {},
},
Expand All @@ -25,6 +26,7 @@ Array [
"offset": 1000,
"parentId": "a",
"serviceName": "opbeans-java",
"skew": 0,
"span": Object {
"transaction": Object {
"id": "a",
Expand All @@ -43,6 +45,7 @@ Array [
"offset": 2000,
"parentId": "a",
"serviceName": "opbeans-java",
"skew": 0,
"span": Object {
"transaction": Object {
"id": "a",
Expand All @@ -61,6 +64,7 @@ Array [
"offset": 3000,
"parentId": "b",
"serviceName": "opbeans-java",
"skew": 0,
"timestamp": 1536763736369000,
"transaction": Object {},
},
Expand All @@ -73,6 +77,7 @@ Array [
"offset": 5000,
"parentId": "c",
"serviceName": "opbeans-java",
"skew": 0,
"span": Object {
"transaction": Object {
"id": "c",
Expand Down
167 changes: 88 additions & 79 deletions ...ails/Transaction/WaterfallContainer/Waterfall/waterfall_helpers/waterfall_helpers.test.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -4,92 +4,101 @@
* you may not use this file except in compliance with the Elastic License.
*/

import { groupBy, indexBy } from 'lodash';
import { Span } from 'x-pack/plugins/apm/typings/Span';
import { Transaction } from 'x-pack/plugins/apm/typings/Transaction';
import { getWaterfallItems, IWaterfallGroup } from './waterfall_helpers';
import {
getWaterfallItems,
IWaterfallIndex,
IWaterfallItem
} from './waterfall_helpers';

describe('waterfall_helpers', () => {
describe('getWaterfallItems', () => {
it('should order items correctly', () => {
const items: IWaterfallGroup = {
a: [
{
id: 'b',
parentId: 'a',
serviceName: 'opbeans-java',
name: 'GET [0:0:0:0:0:0:0:1]',
duration: 4694,
timestamp: 1536763736368000,
offset: 0,
docType: 'span',
span: {
transaction: {
id: 'a'
}
} as Span
},
{
id: 'b2',
parentId: 'a',
serviceName: 'opbeans-java',
name: 'GET [0:0:0:0:0:0:0:1]',
duration: 4694,
timestamp: 1536763736367000,
offset: 0,
docType: 'span',
span: {
transaction: {
id: 'a'
}
} as Span
}
],
b: [
{
id: 'c',
parentId: 'b',
serviceName: 'opbeans-java',
name: 'APIRestController#productsRemote',
duration: 3581,
timestamp: 1536763736369000,
offset: 0,
docType: 'transaction',
transaction: {} as Transaction
}
],
c: [
{
id: 'd',
parentId: 'c',
serviceName: 'opbeans-java',
name: 'SELECT',
duration: 210,
timestamp: 1536763736371000,
offset: 0,
docType: 'span',
span: {
transaction: {
id: 'c'
}
} as Span
}
],
root: [
{
id: 'a',
serviceName: 'opbeans-java',
name: 'APIRestController#products',
duration: 9480,
timestamp: 1536763736366000,
offset: 0,
docType: 'transaction',
transaction: {} as Transaction
}
]
};
const items: IWaterfallItem[] = [
{
id: 'd',
parentId: 'c',
serviceName: 'opbeans-java',
name: 'SELECT',
duration: 210,
timestamp: 1536763736371000,
offset: 0,
skew: 0,
docType: 'span',
span: {
transaction: {
id: 'c'
}
} as Span
},
{
id: 'b',
parentId: 'a',
serviceName: 'opbeans-java',
name: 'GET [0:0:0:0:0:0:0:1]',
duration: 4694,
timestamp: 1536763736368000,
offset: 0,
skew: 0,
docType: 'span',
span: {
transaction: {
id: 'a'
}
} as Span
},
{
id: 'b2',
parentId: 'a',
serviceName: 'opbeans-java',
name: 'GET [0:0:0:0:0:0:0:1]',
duration: 4694,
timestamp: 1536763736367000,
offset: 0,
skew: 0,
docType: 'span',
span: {
transaction: {
id: 'a'
}
} as Span
},
{
id: 'c',
parentId: 'b',
serviceName: 'opbeans-java',
name: 'APIRestController#productsRemote',
duration: 3581,
timestamp: 1536763736369000,
offset: 0,
skew: 0,
docType: 'transaction',
transaction: {} as Transaction
},
{
id: 'a',
serviceName: 'opbeans-java',
name: 'APIRestController#products',
duration: 9480,
timestamp: 1536763736366000,
offset: 0,
skew: 0,
docType: 'transaction',
transaction: {} as Transaction
}
];

const entryTransactionItem = items.root[0];
expect(getWaterfallItems(items, entryTransactionItem)).toMatchSnapshot();
const childrenByParentId = groupBy(
items,
hit => (hit.parentId ? hit.parentId : 'root')
);
const itemsById: IWaterfallIndex = indexBy(items, 'id');
const entryTransactionItem = childrenByParentId.root[0];
expect(
getWaterfallItems(childrenByParentId, itemsById, entryTransactionItem)
).toMatchSnapshot();
});
});
});
53 changes: 48 additions & 5 deletions ...onDetails/Transaction/WaterfallContainer/Waterfall/waterfall_helpers/waterfall_helpers.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -42,6 +42,7 @@ interface IWaterfallItemBase {
duration: number;
timestamp: number;
offset: number;
skew: number;
childIds?: Array<IWaterfallItemBase['id']>;
}

Expand All @@ -68,6 +69,7 @@ function getTransactionItem(
duration: transaction.transaction.duration.us,
timestamp: new Date(transaction['@timestamp']).getTime() * 1000,
offset: 0,
skew: 0,
docType: 'transaction',
transaction
};
Expand All @@ -81,6 +83,7 @@ function getTransactionItem(
duration: transaction.transaction.duration.us,
timestamp: transaction.timestamp.us,
offset: 0,
skew: 0,
docType: 'transaction',
transaction
};
Expand All @@ -97,6 +100,7 @@ function getSpanItem(span: Span): IWaterfallItemSpan {
timestamp:
new Date(span['@timestamp']).getTime() * 1000 + span.span.start.us,
offset: 0,
skew: 0,
docType: 'span',
span
};
Expand All @@ -110,26 +114,61 @@ function getSpanItem(span: Span): IWaterfallItemSpan {
duration: span.span.duration.us,
timestamp: span.timestamp.us,
offset: 0,
skew: 0,
docType: 'span',
span
};
}

function getClockSkew(
item: IWaterfallItem,
itemsById: IWaterfallIndex,
parentTransactionSkew: number
) {
// calculate clock skew for transactions with parents
if (item.docType === 'transaction' && item.parentId) {
const parentItem = itemsById[item.parentId];

// determine if child starts before the parent, and in that case how much
const diff = parentItem.timestamp + parentItem.skew - item.timestamp;

// If child transaction starts after parent span there is no clock skew
if (diff < 0) {
return 0;
}

// latency can only be calculated if parent duration is larger than child duration
const latency = Math.max(parentItem.duration - item.duration, 0);
const skew = diff + latency / 2;
return skew;
}

return parentTransactionSkew;
}

export function getWaterfallItems(
childrenByParentId: IWaterfallGroup,
itemsById: IWaterfallIndex,
entryTransactionItem: IWaterfallItem
) {
function getSortedChildren(item: IWaterfallItem): IWaterfallItem[] {
function getSortedChildren(
item: IWaterfallItem,
parentTransactionSkew: number
): IWaterfallItem[] {
const skew = getClockSkew(item, itemsById, parentTransactionSkew);
const children = sortBy(childrenByParentId[item.id] || [], 'timestamp');

item.childIds = children.map(child => child.id);
item.offset = item.timestamp - entryTransactionItem.timestamp;
item.skew = skew;

const deepChildren = flatten(children.map(getSortedChildren));
const deepChildren = flatten(
children.map(child => getSortedChildren(child, skew))
);
return [item, ...deepChildren];
}

return getSortedChildren(entryTransactionItem);
return getSortedChildren(entryTransactionItem, 0);
}

function getTraceRoot(childrenByParentId: IWaterfallGroup) {
Expand Down Expand Up @@ -179,9 +218,13 @@ export function getWaterfall(
hit => (hit.parentId ? hit.parentId : 'root')
);
const entryTransactionItem = getTransactionItem(entryTransaction);
const items = getWaterfallItems(childrenByParentId, entryTransactionItem);
const itemsById: IWaterfallIndex = indexBy(filteredHits, 'id');
const items = getWaterfallItems(
childrenByParentId,
itemsById,
entryTransactionItem
);
const traceRoot = getTraceRoot(childrenByParentId);
const itemsById: IWaterfallIndex = indexBy(items, 'id');

const getTransactionById = (id?: IWaterfallItem['id']) => {
if (!id) {
Expand Down