Friday, March 6, 2015

Cassandra Compaction and Tombstone Behavior: Leveled vs. SizeTiered Compaction

Compactions in Cassandra can be contentious due to their impact on I/O load as well as increased disk space availability requirements. A primer in compaction will be provided, and the differences in Cassandra's data organization and tombstone handling between Leveled and SizeTiered compaction strategies will be discussed.

What is compaction?

Compaction is a maintenance process which re-organizes SSTables to optimize data structures on disk as well as reclaim unused space. It is helpful to understand how Cassandra handles commits to the datastore to understand why compaction is so important to Cassandra's performance and health.

When writing to Cassandra, the following steps take place:

  1. The commit is logged to disk in a commit log entry, and inserted into an in-memory table
  2. Once the memtable reaches a limit on entries, it is flushed to disk
  3. Entries from the memtable being flushed are appended to a current SSTable in the column family
  4. If compaction thresholds are reached, a compaction is run
The key takeaway is that the entry is appended to the current SSTable. Since SSTable entries are immutable, a row in an SSTable cannot be changed once written. For example, a simple schema for a column family might look like:

CREATE TABLE simple_cf (
 id int,
 text1 text,
 text2 text,
 PRIMARY KEY (id)
)

Some initial data is populated into the column family:

cqlsh:test> INSERT INTO simple_cf (id, text1, text2) VALUES (1, 'This is a test 1', NULL);
cqlsh:test> UPDATE simple_cf SET text2='This is a test 2' WHERE id=1;

The Cassandra server is flushed (nodetool flush). A (partial) update is performed after the flush:

cqlsh> UPDATE simple_cf SET text2='This is a test 3' WHERE id=1;

The Cassandra server is flushed again (nodetool flush). The SSTables representing column family simple_cf are introspected. Note how the first entry reflects both the INSERT and subsequent UPDATE in one SSTable row because they were both executed before flushing from the memtable; Cassandra will attempt to consolidate row entries in the memtable where possible before writing:

stu$ sstable2json test-simple_cf-jb-1-Data.db
[
{"key": "00000001","columns": [["","",1425595340998000], ["text1","This is a test 1",1425595340998000], ["text2","This is a test 2",1425595367745000]]}
]
stu$ sstable2json test-simple_cf-jb-2-Data.db
[
{"key": "00000001","columns": [["text2","This is a test 3",1425595457034000]]}
]

Reviewing the data in the simple_cf colulmn family inserted, above:

cqlsh:test> SELECT * FROM simple_cf WHERE id=1;
id | text1 | text2
----+------------------+------------------
1 | This is a test 1 | This is a test 3
(1 rows)

When the SELECT is issued against the record inserted, Cassandra will need to perform a read request against both SSTables in order to reconstruct the single record. During compaction, these two SSTable entries will be merged into one. Running compaction against the simple_cf column family (nodetool compact) will result in a single new SSTable replacing the original two (above):

stu$ sstable2json test-simple_cf-jb-3-Data.db
[
{"key": "00000001","columns": [["","",1425595340998000], ["text1","This is a test 1",1425595340998000], ["text2","This is a test 3",1425595457034000]]}
]

In addition to user data, SSTables can also contain various entities necessary to support Cassandra's eventual consistency paradigm. Deletions are a great example:

cqlsh:test> DELETE FROM simple_cf WHERE id=1;

After flushing to disk (nodetool flush), introspecting SSTables for simple_cf reveals:

stu$ sstable2json test-simple_cf-jb-3-Data.db
[
{"key": "00000001","columns": [["","",1425595340998000], ["text1","This is a test 1",1425595340998000], ["text2","This is a test 3",1425595457034000]]}
]
stu$ sstable2json test-simple_cf-jb-4-Data.db
[
{"key": "00000001","metadata": {"deletionInfo": {"markedForDeleteAt":1425596205184000,"localDeletionTime":1425596205}},"columns": []}
]

It is possible to see that Cassandra notes the row deletion as a new SSTable entry. Re-inserting new data, flushing, removing a column from the row, and then flushing again:

cqlsh:test> INSERT INTO simple_cf (id, text1, text2) VALUES (2, 'Testing1', 'Testing2');
cqlsh:test> SELECT * FROM simple_cf WHERE id=2;
id | text1 | text2
----+----------+----------
2 | Testing1 | Testing2
(1 rows)
-- FLUSH TO DISK (nodetool flush)
cqlsh:test> DELETE text2 FROM simple_cf WHERE id=2;
cqlsh:test> SELECT * FROM simple_cf WHERE id=2;
id | text1 | text2
----+----------+-------
2 | Testing1 | null
(1 rows)
-- FLUSH TO DISK (nodetool flush)

Introspecting new SSTables after flushing reveals:

stu$ sstable2json test-simple_cf-jb-6-Data.db
[
{"key": "00000002","columns": [["","",1425596539939000], ["text1","Testing1",1425596539939000], ["text2","Testing2",1425596539939000]]}
]
stu$ sstable2json test-simple_cf-jb-7-Data.db
[
{"key": "00000002","columns": [["text2","54f8e0be",1425596606981000,"d"]]}
]

Cassandra noted the column deletion using a "tombstone" record, appended to the current SSTable. The compaction process will eventually merge all SSTable updates and recover space used by deleted data (and the associated tombstones for deleted data).

Triggering a manual compaction and introspecting the resulting SSTable reveals:

stu$ sstable2json test-simple_cf-jb-8-Data.db
[
{"key": "00000001","metadata": {"deletionInfo": {"markedForDeleteAt":1425596205184000,"localDeletionTime":1425596205}},"columns": []},
{"key": "00000002","columns": [["","",1425596539939000], ["text1","Testing1",1425596539939000], ["text2","54f8e0be",1425596606981000,"d"]]}
]

The data from multiple SSTable entries have been merged, but the space has not been recovered. Due to Cassandra's distributed nature, notations on deleted data are retained for no less than "gc_grace_seconds" to prevent data from re-appearing on other nodes due to a split brain event in the cluster. Once gc_grace_seconds expires, the data will be removed during compaction:

cqlsh:test> DESCRIBE TABLE simple_cf;
CREATE TABLE simple_cf (
 id int,
 text1 text,
 text2 text,
 PRIMARY KEY ((id))
) WITH
...
 gc_grace_seconds=864000;
...
cqlsh:test> ALTER TABLE simple_cf WITH gc_grace_seconds=10;

Running a second compaction (nodetool compact) after setting gc_grace_seconds to an artificially low value results in the following SSTable content:

stu$ sstable2json test-simple_cf-jb-9-Data.db
[
{"key": "00000002","columns": [["","",1425596539939000], ["text1","Testing1",1425596539939000]]}
]

Because gc_grace_seconds has expired, the tombstones are removed.

Why do we care about compactions and compaction strategies?

Compaction is a fundamental maintenance task necessary to support Cassandra's on-disk data structure. Since all Cassandra SSTable entries are immutable, any updates or deletes to a row requires a new SSTable entry to be recorded. Values which are deleted are replaced by a tombstone record for the length of time configured in gc_grace_seconds. Cassandra reconciles updates by determining the most recent data, and then only returns the valid data to the client.

This means that:

  • Deletions and storage space recovery are lazy
  • A row can fragment across more than one SSTable
  • A tombstone is a fragment of a row
  • Reading a row requires reconciling all SSTable entries, and determining the most recent set of data before returning data to the caller.
  • Increased row fragments spread across multiple SSTables increases response latency.

At Polyvore, we use Cassandra extensively in production and as our data grows, so does our understanding of how Cassandra organizes its data on disk. When transitioning our user feed processing from MySQL to Cassandra, we wanted to explore how different compaction strategies affected tombstone handling (in our workload, there are many reads from the user feed as well as many updates). We undertook this investigative exercise when we ran into three notable findings on one of our clusters:

  1. The size of the tombstones in our user feed processing table approached the size of our live dataset, and
  2. We approached a level of disk utilization which would prevent further size tiered compactions from taking place.
  3. Fragmentation was noted in the SSTable - especially on wide rows.

The Test:

To test our theories, we created the following schema on a single node test cluster:

-- Table with current schema; covers test case SizeTiered
-- Please note that the sstable_size_in_mb option was set intentionally low
-- to force many compactions. Cassandra recommends this value be set
higher in production use.
CREATE KEYSPACE test WITH REPLICATION={'class':'NetworkTopologyStrategy', 'datacenter1':1};
USE test;
CREATE TABLE unprocessed_size (
  user_id int,
  reason_type text,
  insert_tuid timeuuid,
  object_class text,
  object_id int,
  reason_data text,
  PRIMARY KEY ((user_id, reason_type), insert_tuid)
) WITH CLUSTERING ORDER BY (insert_tuid DESC) AND
  bloom_filter_fp_chance=0.010000 AND
  caching='KEYS_ONLY' AND
  comment='' AND
  dclocal_read_repair_chance=0.000000 AND
  gc_grace_seconds=900 AND
  index_interval=128 AND
  read_repair_chance=0.100000 AND
  replicate_on_write='true' AND
  populate_io_cache_on_flush='false' AND
  default_time_to_live=0 AND
  speculative_retry='99.0PERCENTILE' AND
  memtable_flush_period_in_ms=0 AND
  compaction={'class': 'SizeTieredCompactionStrategy', 'min_threshold' : 2, 'min_sstable_size': 1048576} AND
  compression={'sstable_compression': 'LZ4Compressor'};
-- Table with current schema; covers test case Leveled
CREATE TABLE unprocessed_leveled (
  user_id int,
  reason_type text,
  insert_tuid timeuuid,
  object_class text,
  object_id int,
  reason_data text,
  PRIMARY KEY ((user_id, reason_type), insert_tuid)
) WITH CLUSTERING ORDER BY (insert_tuid DESC) AND
  bloom_filter_fp_chance=0.010000 AND
  caching='KEYS_ONLY' AND
  comment='' AND
  dclocal_read_repair_chance=0.000000 AND
  gc_grace_seconds=900 AND
  index_interval=128 AND
  read_repair_chance=0.100000 AND
  replicate_on_write='true' AND
  populate_io_cache_on_flush='false' AND
  default_time_to_live=0 AND
  speculative_retry='99.0PERCENTILE' AND
  memtable_flush_period_in_ms=0 AND
  compaction={'class': 'LeveledCompactionStrategy', 'sstable_size_in_mb': 1} AND
  compression={'sstable_compression': 'LZ4Compressor'};

The two column families share the same structure, the only difference being the compaction strategy configured. 500,000 rows of random data were inserted into these tables with varying TTLs. Then:

  1. The TTLs were allowed to expire
  2. The gc_grace period was allowed to expire
  3. SSTables were dumped to JSON and reviewed
  4. Repeated 3 times:
    1. Major compactions forced against the datasets
    2. SSTables were dumped to JSON and reviewed

SizeTiered Compaction:

When Cassandra was first released, the only compaction strategy available was SizeTiered. Size tiered compaction allows the operator to defines the maximum number of SSTables which should make up the backend storage of a given column family. When the maximum number of SSTables is reached, Cassandra will merge the existing SSTables into a single new table.

Tombstones whose gc_grace period has been met will be removed.

SizeTiered compaction is a general purpose algorithm which is suitable for a wide range of schema designs and data access patterns. The downside to SizeTiered compaction is that over time SSTables may suffer from fragmentation (where a row's current data is stored across more than one SSTable on disk), and that the compaction process itself is I/O and storage intensive. In fact, the worst case scenario for a SizeTiered compaction is twice the space of the sum of all SSTables involved in compaction. This means that it's possible for a 100GB column family to require an additional 100GB of disk space to successfully compact. In that scenario assuming a maximum of four SSTables, the next full compaction would require 400GB of available space (800GB total needed during compation). Needless to say, requiring storage to be capped at 50% of capacity is non-ideal for some workloads.

The second issue with SizeTiered compaction is that of fragmented rows. A fragmented row is a row which is stored across multiple backend SSTables. This can occur very easily when an existing row is updated; since SSTables are immutable, an update to an existing row which is appended to one of the in-use SSTables. If this update occurs on a different SSTable from where the record was originally stored, Cassandra must reconcile all of the rows in order to determine which one is the most recent. This results in additional non-sequential I/O and operations for any read against the fragmented row.

Once the space requirement for compaction exceeds available space on the host, compaction is no longer possible without intervention. It's easy to see how an inability to compact combined with SizeTieredCompaction could result in serious read latency increases over the long term. Additionally, if compactions cannot be performed tombstones will never be reaped.

Leveled Compaction:

Given an understanding of how Cassandra stores data, is it possible to reduce storage space contention as well as reduce fragmentation? Depending on workload and schema design, possibly. Leveled compaction requires the operator to define the maximum size for each SSTable. SSTables will be grouped into levels, with each subsequent level equal to 10 times the size of the prior. So, assuming a maximum table size of 10MB:

When a record is inserted, it's immediately placed into a L0 (Level 0) SSTable. The L0 SSTables are immediately compacted into Level 1 SSTables; duplicate/updated rows are merged. When 10 L1 tables are in place, they are compacted and merged into a set of L2 tables. This process continues indefinitely.

By merging SSTables during leveled compaction there is a high likelihood that fragmented rows will be combined during each leveled compaction, subsequently resulting in better guarantees of a single row being localized to one SSTable. For read-heavy workloads, this can reduce latency significantly as substantially fewer reads across SSTables are required. Even with many updates - and even with partial row updates - leveled compaction helps reduce fragmentation by frequently compacting leveled tables as the data size grows.

Of course, there are tradeoffs... the leveled compaction process itself is potentially more resource intensive than a SizeTiered compaction strategy as all 10 SSTables in any given level must be read during compaction. The key takeaway, however, is that Tombstones will only be reaped when the impacted SSTable "moves"/is compacted to the next level and gc_grace has expired. Triggering a manual compaction is not sufficient to remove the tombstones.

When to consider SizeTiered Compaction:

Consider SizeTiered Compaction when:

  • There is uncertainty of which compaction strategy is best; SizeTiered Compaction provides a good set of tradeoffs for acceptable performance under most workloads.
  • Mixed workload of reads, updates, and deletes; avoiding updates to existing rows helps avoid fragmentation.
  • Read latency is not important; the upper bound to fragmentation is the number of SSTables representing the column family.
  • Tombstones make up a substantial portion of at rest data, and are reaped via manual compaction.
  • There is sufficient free space to store 100% growth of the largest column family.

When to consider Leveled Compaction:

Consider Leveled Compaction when:

  • Read-heavy workload; many reads, some updates
  • Workloads which frequently update existing rows
  • Read latency is important; the upper bound to fragmentation is reduced as the number of SSTables in the column family grows (due to the leveled compaction process)
  • Tombstone space recovery is not important; tombstones will not be reaped until an SSTable moves to the next compaction tier (i.e. moves from L1 to L2).
  • There is not sufficient free space to store 100% growth of the largest column family. Leveled compaction requires 10 times available storage space of the largest SSTable in a column family.

Other findings:

  • Very wide rows are bad for compaction performance; wide rows fragmented across multiple SSTables (especially with partial updates) seem to result in lazy compaction.

Final Thoughts:

Cassandra brings robust, distributed data storage to any application able to utilize its API. It also offers CQL, a language strikingly similar to SQL's DML and DDL which offers less of a learning curve than some competing solutions. Ease of use and being a distributed key/value store, however, does not necessarily translate to success: the DBA or developer must understand how Cassandra organizes and maintains its underlying data to effectively design a schema which will scale under the load of millions of users.

What's Next:

  • Investigation of Date Tiered Compaction behavior

103 comments:

  1. I feel that Leveled Compaction is good for general workloads, and Sized-Tiered Compaction is good for a specialized workload.
    www.essayhelpuk.com/coursework
    http://stackoverflow.com

    ReplyDelete
  2. A terrific packed of reading and newest things I got for the approach. Looking forward more here!
    Walking Dead jacket At NewAmerican

    ReplyDelete
  3. Enjoy your game clash of clans with free clash of clans gems and win all fights. These clash of clans hack tool also have free clash of clans gems generator.

    ReplyDelete
  4. Kids perform recklessly and therefore are more vulnerable to hazards compared to us; we offer the means to fix their problem that is use of Durable Rubber Lawn Mats For Course. HEAVY DUTY RUBBER GRASS MATS

    ReplyDelete
  5. Thank you so much for your nice post. I Think it is very helpful post.
    Clipping Path Service India

    ReplyDelete
  6. I am hoping the same best work from you in the future as well.
    free amazon gift card codes generator no surveys

    ReplyDelete
  7. Great information provided how to get gems in dragon city to get cheat dragon city at zero coins than visit here.

    ReplyDelete
  8. Reading the work you pay for can help you find things that you miss or ignore in your own writing. This can be grammatical structures, citations, style and even the personality of your writing. Identifying the things that make a paper good will help you to make your own writing better.

    ReplyDelete
  9. Once I've been confused while choosing the best moment for SIZETIERED compaction. With professional homework help for high school students you will never get in trouble while writing any "coding" assignments. The ease of usage never means that the result will be correct.

    ReplyDelete
  10. You articulated this blog with all key elements. It sounds really effective to read, I must catch up with this.
    Blade Coat

    ReplyDelete
  11. Here is the homepage for hack facebook password , follow easy step to prevent account expiration.

    ReplyDelete
  12. I am glad it was an enjoyable experience for you. I think that you should definitely do it again sometime and hopefully I will be able to make it to that one.
    pay someone to do your assignment

    ReplyDelete
  13. Custom essay writing service have good ambition and aim. Many are there to assist the students those who are not good in writing. Essay writing is considered a very high level profession and schools are emphasizing a lot for developing great essay writers in childhood stages of students. The custom essay writing service provides the guidelines and sample papers for students.In order to make their children understand the value of essay writings it is very smart of them to arrange such trips. It encourages them all to produce high quality content.

    ReplyDelete
  14. Great Article, Many of college and school student looking for professional online paper writing service at affordable price. Thanks

    ReplyDelete
  15. some tricks to get the access the free resource for moviestar planet game and generte the vip coins and get access its msp hack here online to generate its gold and coins.

    ReplyDelete
  16. E Discovery Needs Investment in Appropriate Software Structure and Engineering Skills in Lawyers best essay writing service bestessaywriting.com in cheap price Use Machining Subcontractors to Meet Engineering Needs

    ReplyDelete
  17. Your blog was too good. i really appreciate with your blog.Thanks for sharing.
    http://iplauction2016.in/2016-gujarat-lions-gl-team-squad-rajkot-players-list-captain-name-jersey-logo/
    http://iplauction2016.in/rps-2016-team-squad-players-list-new-logo-jersey-images-wallpapers/
    http://iplauction2016.in/rcb-2016-team-squad-new-players-list-jersey-logo-images/

    ReplyDelete
  18. O aplicativo dedicado de bate-papo surgiu das cinzas do Beluga Messenger, cliente de bate-papo que foi comprado pelo baixar Facebook no começo do ano. A versão para iOS estará disponível em breve, mas a versão para Android já está disponível nesse link.
    Source: facebook movel baixar

    As versões anteriores do Mobogenie app estão cada vez mais populares entre os usuários, oferecendo maneiras simples e atraentes para sincronizar telefones sem aborrecimentos.
    Source: mobogenie
    ----------
    Signture:
    Baixar whatsapp

    ReplyDelete
  19. Truly, this article is really one of the very best in the history of articles. I am a antique ’Article’ collector and I sometimes read some new articles if I find them interesting.
    Assignment Help

    ReplyDelete
  20. Great site and a great topic as well I really get amazed to read this. It’s really good. I like viewing web sites which comprehend the price of delivering the excellent useful resource free of charge.
    Assignment Help

    ReplyDelete
  21. I would like to thank you for the efforts you have made in writing this article. I am hoping the same best work from you in the future as well. . buy sunglasses

    ReplyDelete
  22. Nice blog and absolutely outstanding. You can do something much better but I still say this perfect. Keep trying for the best.
    Assignment Help

    ReplyDelete

  23. I like this a lot. Thank you for sharing. I'm always looking for upcycles like this. In the end, you don't know it was a shipping pallet to begin with!
    raze 2 game
    play raze 3 unblocked
    return man 2 football
    strike force heroes hacked
    strike force heroes 2 hacked
    play run 2 unblocked
    run 3 unblocked
    sports heads
    head soccer

    ReplyDelete
  24. If someone is looking to buy assignment or pay for custom asignment help can rely on our service tailor-made essay and read about the experience of the students who used our assignment writing service.

    ReplyDelete
  25. I like this post, it's useful with me. Thank you very much!
    Auto reviews

    ReplyDelete
  26. I think your post is interesting. It's very usefull with me. Thank you very much!
    baixar whatsapp gratis

    ReplyDelete
  27. When you're tired, you want to relax after a stressful working hours, you need to have time to take care of the kids active.
    Please visit our website and play exciting flash games.Thanks you for sharing!
    Friv 4

    ReplyDelete
  28. Banyak orang yang merasa terganggu dengan penyakit ambeien. Karena ambeien merupakan penyakit yang munculnya di bagian dubur atau anus. Tapi ternyata pengobatan ambeien tidak harus selalu secara medis namun kini ada http://wasirambeienherbal.com/cara-mengobati-benjolan-wasir-secara-alami.html. Memang cara pengobatan itu tergantung dari si penderita. Bisa mengobati secara medis maupun secara tradisional. Semuanya bisa dilakukan sesuai dengan keinginan penderita mana yang dirasa lebih mudah. Untuk lebih jelasnya silahkan baca artikel kami selengkapnya

    Blog ini menjual obat herbal kutil kelamin, karena Jika penyakit ini terus dibiarkan maka gejala juga akan terasa menyakitkan. Mengenai proses munculnya, kutil pada pria ini bisa hadir dalam bentuk datar atau berukuran besar dan berkelompok. Ciri yang paling umum dari kutil kelamin ini adalah bentuknya yang menyerupai kembang kol. untuk cara pemesanana silahkan kunjungpengobatan kutil kelamin tanpa operasi



    http://www.obatdenature.com/obat-kemaluan-keluar-nanah/Dan kondisi ini dapat semakin parah dan kemudian menimbulkan berbagai macam komplikasi seperti peradangan sendi dan infeksi jantung. Hal yang seperti ini dapat dicegah dengan mengenali gejala awalnya, sehingga penyakit ini tidak bertambah parah. untuk cara pemesanana silahkan kunjunghttp://se-intelligence.com/mengobati-kemaluan-keluar-nanah.html


    http://wasirambeienherbal.com/cara-mengobati-benjolan-wasir-secara-alami.html kekurangan dan kelebihannya. Misalnya saja dengan pengobatan secara medis, masih mungkin ada efek dari penyakit tersebut. Karena banyak pengobatan medis yang menggunakan bahan-bahan kimia. Namun cara mengobati ambeien secara tradisional juga sama halnya dengan pengobatan medis. Ada kekurangan dan kelebihan. Tapi tidak ada salahnya jika pengobatan secara tradisional pada penyakit ambeien dilakukan sejak awal. Untuk pemesanan obatnya ilahkan kunjungi website kami

    Klik disini untuk pemesanan obat kutil kelamin denature, tentu saja kita agak seram membayangkan hal ini jika terjadi pada kita, tapi setidaknya cara ini memang terbaik karena dilakuka dengan bersih dan efisien. untuk cara pemesanana silahkan kunjungpengobatan kutil di kemaluan tanpa operasi



    http://www.obatdenature.com/obat-kemaluan-keluar-nanah/Dan kondisi ini dapat semakin parah dan kemudian menimbulkan berbagai macam komplikasi seperti peradangan sendi dan infeksi jantung. Hal yang seperti ini dapat dicegah dengan mengenali gejala awalnya, sehingga penyakit ini tidak bertambah parah. untuk detail tentang gonore silahkan baca artikelhttp://bonjourdeluxe.com/nanah-keluar-dari-kemaluan.html


    ReplyDelete
  29. All the best blogs that is very useful for keeping me share the ideas
    of the future as well this is really what I was looking for, and I am
    very happy to come here. Thank you very much
    earn to die play
    earn to die
    earn to die 3
    Hi! I’ve been reading your blog for a while now and finally got the
    earn to die 4
    courage to go ahead and give youu a shout out from
    earn to die 6
    Austin Texas! Just wanted to tell
    earn to die 5
    you keep up the fantastic work!my weblog
    age of war
    Hi! I’ve been reading your blog for a while now and finally got the
    happy wheels
    strike force heroes
    slither io
    slitherio

    ReplyDelete
  30. Thanks for the best was very useful for me.keep sharing such ideas in the future as well. Thanks for giving me the useful information. I think I need it!
    Happy Wheels , FNAF World , Five Nights At Freddy's

    ReplyDelete
  31. A nova versão Facebook baixar para Windows Phone foi totalmente reformulado, com um desempenho mais rápido, uma nova interface de usuário, navegação melhorada, suporte para várias resoluções, tamanhos de telha e muito mais.
    O baixar Mobogenie ainda dá a possibilidade de levar todos os dados do computador para seu celular. Graças a seu simples sistema de transferência de arquivos, você pode mudar imagens, vídeos, músicas, planilhas e até outros arquivos.

    ReplyDelete
  32. Award Winning Interior Designers in Sydney Design4space is now offering 3D rendering services to help individuals in creating aesthetically pleasing interiors. Their designers fully understand their clients’ requirements and create 3D renders as per their ideas and specifications.

    ReplyDelete
  33. Want to know regular updates of Euro Cup 2016????
    Get Euro Cup live Streaming,Euro Cup 2016 Schedule,Euro Cup 2016 Fixture,Euro Cup 2016 Live Streaming,Euro Cup 2016 Live Stream,Euro Cup 2016 Live Score.
    Venue-France,From 10th june-10july. 24 teams,10 stadiums. Stay updated. Watch Euro Cup 2016 Opening Ceremony

    ReplyDelete
  34. Diep.io is a new addition in which you control a tank and shoot down both obstacles and opponents. Diep.io, which is quickly becoming the next Agar.io style game sensation. Diep.io is a funny muliplayer tanks shooting game. Control a tank, shoot opponents and obstacles, upgrade your tank while trying to keep alive.

    ReplyDelete
  35. This is a great article. It gave me a lot of useful information. thank you very much. Can you play more games at :


    red ball 4 | ninjago games | swords and souls | strike force kitty 2 | red ball 3

    ReplyDelete
  36. Loved to read your blog. I would like to http://awriter.org/affordablepapers-com-review
    suggest you that traffic show most people read blogs on Mondays. So it should encourage blogger to write new write ups over the weekend primarily http://awriter.org/affordablepapers-com-review

    ReplyDelete
  37. Thanks for sharing this quality information with us. I really enjoyed reading.
    slither io | wings io | science kombat | tank trouble 4

    ReplyDelete
  38. Welcomes to google terminal keep sharing such ideas in the future as well.
    google snake this was actually EARN TO DIE
    what i was looking for,and i am glad to came here! AGE OF WAR 2
    Hi! I’ve been reading your blog for a while HAPPY WHEELS
    I want you to thank for your time of this wonderful read!!! Slitherio
    Amazing insight you have on this, Slither io This article always blew me BIG FARM

    ReplyDelete
  39. The war between humans, orcs and elves continues. Lead your race through a series of epic battles, using your crossbow to fend off foes and sending out units to destroy castles. Researching and upgrading wisely will be crucial to your success!
    slitherio | unfair mario 2 | age of war 2
    The game controls are shown just under . Movement mechanisms primarily include acceleration and tilting controls.
    cubefield | tank trouble | happy wheels |age of war 3 |
    age of war 2 | duck life

    ReplyDelete
  40. orking Environments specialises in Medical and Commercial workspaces.

    WE are focused on the design and construction of practical, cost-effective, well planned, code compliant, market-place appropriate environments.

    Our consultancy provides a single point of contact throughout all project phases.

    WE cater for a diverse range of clients, projects and budgets, tailoring our service solutions to meet our clients needs.

    WE service micro businesses to multinationals. No job to small.

    Based in Sydney we regularly work in Regional NSW and the ACT and have completed projects in all other major capitals.


    medical fitouts, office fitouts, commercial fitouts, business fitouts, office design, office relocation, project management, commerecial office design

    http://www.workingenvironments.com.au/

    ReplyDelete
  41. Run game is today's hottest games. Run 3 version is most played game, run 2 is the older version, but still favorite players. In addition, return man 2 game is a big competitor of run game. Right behind return man game is cat mario 4 game which has plays No. 4 in the rankings this week.
    Source: tank trouble unblocked and stick war unblocked

    ReplyDelete
  42. We are really grateful for your blog post. You will find a lot of approaches after visiting your post. Great work : contact form | snapchat emoji

    ReplyDelete
  43. The online writing services are become the source of importance for the students where the students can bring the The Perfect Guide on writing like these works. nice post.
    Dissertation writing service usa

    ReplyDelete

  44. I want to share any applications example baixar snapchat , google play and play store. Snapchat is app which everybody like, it's chat app. Baixar google play and play store are two applications of google. It allows you download applications and games which you like. Please, Baixar play store
    to mobile to experience

    ReplyDelete
  45. Fantastic material you have shared with everyone with great writing style. I am very happy to read this post I am coming back soon for more info. custom boxes

    ReplyDelete

  46. Your article helped me together multiple views on the matter. In life there are a lot of the stress and fatigue, you just visit my website or games and apps for your phone

    subway surf, subway surf, subway surf , subway surf, subway surf , subway surf , subway surf, subway surf , subway surf, subway surf

    ReplyDelete
  47. I was on your website and reading your blog. I liked the final thoughts section. This is very informative for every one. [url="http://packagingboxessuppliers.com/printed-packaging-boxes.html"]Get Online Packaging Boxes[/url]

    ReplyDelete
  48. You have written on a very good topic. I really liked the blog. This is very interesting and informative . Thanks for share this with me.[url="http://packagingboxessuppliers.co.uk/diecut-boxes-printing.html"]buy cardboard boxes[/url]

    ReplyDelete
  49. If you love cats, you must check out my blog National Cat Day
    which is solely dedicated to cats. Learn everything you want to know about cats and stay updated. Enjoy with your pets on Cat Day and make her feel special.

    ReplyDelete
  50. This is one of the cult game now, a lot of people enjoy playing them . Also you can refer to the game :
    gold mine strike | pokemon go 2
    The game controls are shown just under . Movement mechanisms primarily include acceleration and tilting controls.
    stickman games | stick war 2 | animal jam 2

    ReplyDelete
  51. Great Post ! I have learned something new from this post.

    Thank you so much for your information.

    clipping path service

    clipping path service

    ReplyDelete
  52. Você quer usar o software baixar facebook no seu celular? Você pode acessar esta web que você pode baixá-lo e muitos softwares diferentes. Esta web também tem baixar whatsapp. Estes são três software que check-in, bate-papo e compartilhar informações com seus amigos. E download baixar mobogenie que você gerenciar todas as aplicações no celular. Todos são gratuitos. Tenha um dia divertido!

    ReplyDelete
  53. Mostly people have all the same things when they are writing academic task or any other writing, especially light music most people like during the writing.

    subway surf , baixar subway surf, subway surf download , download subway surf

    ReplyDelete
  54. Thanks I have read your article, it is very interesting and exciting
    download go launcher, go launcher apk, go launcher , go launcher androi,

    ReplyDelete
  55. Mostly people have all the same things when they are writing academic task or any other writing, especially light music most people like during the writing.
    dream league soccer download , dream league soccer apk , download dream league soccer , dream league soccer

    ReplyDelete
  56. You need to have time to take care of the active. It in fact was a amusement account it. Look advanced to far added agreeable from you.
    banana kong ,
    banana kong baixar ,
    baixar banana kong ,
    download banana kong ,
    banana kong

    ReplyDelete
  57. Life becomes more interesting and wonderful when you share your memorable moments with friends and family through unique photographs. You can create your own unique style impressed with image editing software. And after hours of work stress you can also

    tank trouble, tank trouble 2, tank trouble games, tank trouble

    ReplyDelete
  58. Your article helped me together multiple views on the matter. In life there are a lot of the stress and fatigue, you just visit my website or games and apps for your phone

    clash royale game, clash royale apk , download clash royale , clash royale

    ReplyDelete
  59. These credits normally have a lower financing cost than private advances. Be that as it may, there has not been an expansion in some of these advances' most extreme sums since 1992. This implies you really won't not have the capacity to pay for the greater part of your school costs with these advances. Subsequently private understudy advances may be your lone option. Payday Loans San-diego

    ReplyDelete
  60. Everyone loves the look and feel of a clean home. Thanks for choosing this topic for post and update me. Game Stick RPG 2 looks like your real life, you can get everything you want, Ninja Games Free is a common playground game, return man saves your progress, with Potty Racers do you want to fly to Mars with me?

    ReplyDelete
  61. Happy happy new year.Have a best and happy new year.
    Celibrate with wishes to others eg friends, parents, brothers and relatives.
    To bring close them with yourself.
    Best New Year SMS 2017
    New Year 2017 Wishes

    ReplyDelete
  62. The best choice open to you when you are anticipating recording liquidation understudy advances is to counsel either the moneylender or the chairman in your school that handles understudy credits and in addition sites of concerned powers to locate a workable answer for your budgetary hardships. Car Title Loans Chicago

    ReplyDelete
  63. Obviously the legislature can't generally ensure that an understudy will be sufficiently mindful to pay back the advances, they simply ensure the they will pay the bank for the advance, if the understudy abandons them. This obviously wipes out the cost and bother for the bank of pursuing down understudies afterward. Check Cashing San-diego

    ReplyDelete
  64. Awesome article you have post with great manners, I am very happy to see this here I want to say that you are doing a great job. hang tags designers

    ReplyDelete
  65. The regularly scheduled installment is $39 more as analyzed when the credit was secured under the old rate of 3.4% (Phillips, 2013). An inconsequential sum for the built up worker however for the as of late procured representative who is simply beginning his or her vocation this can be a weight. check cashing

    ReplyDelete
  66. I have been searching out for this similar kind of post for past a week and hardly came across this. Thank you very much and will look for more postings from you. I like play game five nights at freddy’s 4, game word cookies game , game word cookies answers , hotmail sign in and hotmail login, and u? I hope people visit my website.

    ReplyDelete
  67. We will ask our IT department at cheap custom writing to solve this issue. Maybe that will help you out

    ReplyDelete
  68. Vea también algunas frases de whatsapp y estados para whatsapp de amor que se compartirán con usted.estados para whatsapp
    Frases para whatsappGracias por tu información

    ReplyDelete

  69. The share your really gives us excitement. Thanks for your sharing. If you feel tired at work or study try to participate in our games to bring the most exciting feeling. Thank you!
    hotmail sign in | red ball game

    ReplyDelete
  70. Thank you, you will give a better article and draw very has a good article .. more articles!

    PokerOnline Terpercaya
    agen poker terbaik
    judi qq
    bandarq

    ReplyDelete
  71. If you need a hacker for whatsapp hack, email hack, phone hack, facebook hack, cheating spouse, general monitoring etc. Contact reputablehacker@gmail.com

    ReplyDelete