MongoDump

## MongoDump

Normal db dump

```bash
$ mongodump -db <dbname> --out /home/data/backup-<dbname>
```

[Mongo Dump Reference](http://docs.mongodb.org/manual/reference/program/mongodump/#bin.mongodump)


## Stream Backup

Solution to do backup when you don't have enought disk space.

```bash
$ mongo-dump-stream mongodb://localhost/<dbname> 
| ssh root@other-server-here.com mongo-load-stream mongodb://localhost/<dbname>
```

## Restore Backup

```bash
$ mongorestore --db <dbname> dump/<dbname>/
```

## Get Usable Sites

```
db.<collection>.find({$and:[   
    {html:{$exists : true}},
    {html:{$ne : ""}},
    {html: /\w{16,}/i }
]}).pretty()
> it 
> it
```

Modify Usable <collection> to add a flag:
```

db.<collection>.update(
    {$and:[  
        {html:{$exists : true}},
        {html:{$ne : ""}},
        {html:{$ne : "滚粗!"}},
        {html:{$ne : "\n"}},
        {html:{ $not: /^403.*Forbidden.*/i }},
        {title:{ $not: /.*404.*/i }},
        {title:{ $not: /.*error.*404.*/i }},
        {title:{ $not: /.*error.*500.*/i }},
        {title:{$ne : "Not Found"}},
        {html: /\w{16,}/i }
    ]},
   { $set: { usable : true } },
   { multi: true }
);
```

## Dump a set of usable files

Particular set dump [for one collection](http://stackoverflow.com/questions/16347134/how-to-use-mongodump-for-1-collection)

To get the subset [see reference](http://stackoverflow.com/questions/7828817/is-it-possible-to-mongodump-the-last-x-records-from-a-collection):

```bash
$ mongo
> use <dbname>
> db.<collection>.find({ usable : true }).count()
248699
> db.<collection>.find({ usable : true }).sort({_id:1}).skip(248699 - 300).limit(1)
<mongo-hash>
```

```bash
$ mongodump --db <dbname> --collection <collection>  --query '{ usable : true , _id: {$gte: ObjectId("<mongo-hash>")} }' --out /home/data/usable-300 
```

i.e.

```
{ "_id" : ObjectId("XXXXXXXXXXXXXX"), "created" : ISODate("2015-05-02T07:38:04.200Z"), "updated" : ISODate("2015-05-08T20:55:40.555Z"), "url" : "http://secret-url.com", ....

$ mongodump --db <dbname> --collection <collection>  --query '{ usable : true , _id: {$gte: ObjectId("55447edcad0b715255de2e05")} }' --out /home/data/usable-300 
connected to: 127.0.0.1
2015-05-28T08:02:35.347+0000 DATABASE: <dbname>     to     /home/data/usable-300/<dbname>
2015-05-28T08:02:35.351+0000    <dbname>.<collection> to /home/data/usable-300/<dbname>/<collection>.bson
2015-05-28T08:02:35.894+0000             300 documents
2015-05-28T08:02:35.894+0000    Metadata for <dbname>.<collection> to /home/data/usable-300/<dbname>/<collection>.metadata.json
```