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var defragmentationUtil = (function() {
load("jstests/sharding/libs/find_chunks_util.js");
// This function creates a randomized, fragmented collection. It does not necessarily make a
// collection with exactly numChunks chunks nor exactly numZones zones.
let createFragmentedCollection = function(
mongos, ns, numChunks, maxChunkFillMB, numZones, docSizeBytes, chunkSpacing) {
assert.commandWorked(mongos.adminCommand({shardCollection: ns, key: {key: 1}}));
createAndDistributeChunks(mongos, ns, numChunks, chunkSpacing);
createRandomZones(mongos, ns, numZones, chunkSpacing);
fillChunksToRandomSize(mongos, ns, docSizeBytes, maxChunkFillMB);
};
let createAndDistributeChunks = function(mongos, ns, numChunks, chunkSpacing) {
const shards = mongos.getCollection('config.shards').find().toArray();
for (let i = -Math.floor(numChunks / 2); i <= Math.floor(numChunks / 2); i++) {
assert.commandWorked(mongos.adminCommand({split: ns, middle: {key: i * chunkSpacing}}));
assert.soon(() => {
let toShard = Random.randInt(shards.length);
let res = mongos.adminCommand(
{moveChunk: ns, find: {key: i * chunkSpacing}, to: shards[toShard]._id});
return res.ok;
});
}
};
let createRandomZones = function(mongos, ns, numZones, chunkSpacing) {
for (let i = -Math.floor(numZones / 2); i < Math.ceil(numZones / 2); i++) {
let zoneName = "Zone" + i;
let shardForZone =
findChunksUtil
.findOneChunkByNs(mongos.getDB('config'), ns, {min: {key: i * chunkSpacing}})
.shard;
assert.commandWorked(
mongos.adminCommand({addShardToZone: shardForZone, zone: zoneName}));
assert.commandWorked(mongos.adminCommand({
updateZoneKeyRange: ns,
min: {key: i * chunkSpacing},
max: {key: i * chunkSpacing + chunkSpacing},
zone: zoneName
}));
}
};
let fillChunksToRandomSize = function(mongos, ns, docSizeBytes, maxChunkFillMB) {
const chunks = findChunksUtil.findChunksByNs(mongos.getDB('config'), ns).toArray();
const bigString = "X".repeat(docSizeBytes);
const coll = mongos.getCollection(ns);
let bulk = coll.initializeUnorderedBulkOp();
chunks.forEach((chunk) => {
let chunkSize = Random.randInt(maxChunkFillMB);
let docsPerChunk = (chunkSize * 1024 * 1024) / docSizeBytes;
if (docsPerChunk === 0) {
return;
}
let minKey = chunk["min"]["key"];
if (minKey === MinKey)
minKey = Number.MIN_SAFE_INTEGER;
let maxKey = chunk["max"]["key"];
if (maxKey === MaxKey)
maxKey = Number.MAX_SAFE_INTEGER;
let currKey = minKey;
const gap = ((maxKey - minKey) / docsPerChunk);
for (let i = 0; i < docsPerChunk; i++) {
bulk.insert({key: currKey, longString: bigString});
currKey += gap;
}
});
assert.commandWorked(bulk.execute());
};
let checkPostDefragmentationState = function(mongos, ns, maxChunkSizeMB, shardKey) {
const oversizedChunkThreshold = maxChunkSizeMB * 1024 * 1024 * 4 / 3;
const chunks =
findChunksUtil.findChunksByNs(mongos.getDB('config'), ns).sort({shardKey: 1}).toArray();
const coll = mongos.getCollection(ns);
const collStats = assert.commandWorked(coll.getDB().runCommand({collStats: ns}));
const avgObjSize = collStats.avgObjSize;
let checkForOversizedChunk = function(
coll, chunk, shardKey, avgObjSize, oversizedChunkThreshold) {
let chunkSize =
coll.countDocuments({key: {$gte: chunk.min[shardKey], $lt: chunk.max[shardKey]}}) *
avgObjSize;
assert.lte(
chunkSize,
oversizedChunkThreshold,
`Chunk ${tojson(chunk)} has size ${
chunkSize} which is greater than max chunk size of ${oversizedChunkThreshold}`);
};
for (let i = 1; i < chunks.length; i++) {
let chunk1 = chunks[i - 1];
let chunk2 = chunks[i];
// Check for mergeable chunks with combined size less than maxChunkSize
if (chunk1["shard"] === chunk2["shard"] && chunk1["max"] === chunk2["min"]) {
let chunk1Zone = getZoneForRange(mongos, ns, chunk1.min, chunk1.max);
let chunk2Zone = getZoneForRange(mongos, ns, chunk2.min, chunk2.max);
if (chunk1Zone === chunk2Zone) {
let combinedDataSize = coll.countDocuments({
shardKey: {$gte: chunk1.min[shardKey], $lt: chunk2.max[shardKey]}
}) * avgObjSize;
assert.lte(
combinedDataSize,
oversizedChunkThreshold,
`Chunks ${tojson(chunk1)} and ${
tojson(chunk2)} are mergeable with combined size ${combinedDataSize}`);
}
}
// Check for oversized chunks
checkForOversizedChunk(coll, chunk1, shardKey, avgObjSize, oversizedChunkThreshold);
}
const lastChunk = chunks[chunks.length - 1];
checkForOversizedChunk(coll, lastChunk, shardKey, avgObjSize, oversizedChunkThreshold);
};
let getZoneForRange = function(mongos, ns, minKey, maxKey) {
const tags = mongos.getDB('config')
.tags.find({ns: ns, min: {$lte: minKey}, max: {$gte: maxKey}})
.toArray();
assert.leq(tags.length, 1);
if (tags.length === 1) {
return tags[0].tag;
}
return null;
};
let waitForEndOfDefragmentation = function(mongos, ns) {
jsTest.log("Waiting end of defragmentation for " + ns);
assert.soon(function() {
let balancerStatus =
assert.commandWorked(mongos.adminCommand({balancerCollectionStatus: ns}));
return balancerStatus.balancerCompliant ||
balancerStatus.firstComplianceViolation !== 'defragmentingChunks';
});
jsTest.log("Defragmentation completed for " + ns);
};
return {
createFragmentedCollection,
checkPostDefragmentationState,
waitForEndOfDefragmentation,
};
})();
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