HBase Backups

HBase BackupsBackups in the Enterprise

Jesse Yates Demai NiJing Chen HeRichard Ding

1 HBase Backups - HBaseCon 2014

Overview• Commonalities• IBM BigInsights• Backups at Salesforce.com• Summary


Commonalities• Per-Table Backups• Stored On HDFS• Full Backup + Incrementals• Fast Restore• Multiple Clusters• Timestamp file layout• Manifest Files for additional info• Merging Backups


IBM BigInsights

HBase Backups - HBaseCon 20144

Backup Solution - IBM• Customer Requirements• Feature Overview• Technical Design• User Interface: CLI and Web UI• Data Structures

• OpenSource through HBASE-7912 HBase Backup/Restore Based on HBase Snapshot


Customer Requirements• Backup and Restore

– Critical requirements from enterprise customers– General solution– Easy-to-use user interfaces: CLI and Web UI– Multiple file systems: HDFS and GPFS*

– Multiple MR frameworks: Hadoop and PSMR*


*GPFS: IBM General Parallel File System

*PSMR: Platform Symphony MapReduce

Feature Overview• Full Backup based on HBase Snapshot• Incremental Backup based on HBase transaction logs• Table-level Incremental Backup• Point-In-Time Restore• On-the-fly and Off-line Convert from HLogs to HFiles • Off-line Merge Backup Images• Self-contained Backup Image with Manifest File• Usability features:

– progress, status, and history reports– purge old Backup Images


Technical Design - Overview• Object: Backup Image• Operations:

– Full Backup– Incremental Backup– Convert– Merge– Restore


Technical Design - Backup Images

Full Backup Table1(Monday)

Full Backup Table2(Tuesday)

Incremental Backup [Table1, Table2] (Wednesday)

Incremental Backup [Table1, Table2] (Thursday)

depends

dependsdepends


Technical Design - Full Backup


$ hbase backup create full hdfs://targetCluster.ibm.com:9000/hbasebackups biginsights:hbasecon_table1

Global DistributedWAL Roll

Take Snapshot

Track WAL Timestamp ThroughZookeeper

Export Snapshot

Generate Manifest

Technical Design - Incremental Backup


$ hbase backup create incremental hdfs://targetCluster.ibm.com:9000/hbasebackups

Global DistributedWAL Roll

Track WAL Timestamp Through ZooKeeper

DistCp WAL Logs into Backup Image

Generate Manifest

Technical Design - Restore


$ hbase restore hdfs://targetCluster.ibm.com:9000/hbasebackups biginsights:hbasecon_table1 biginsights:hbasecon_table1_restore

Create Table Pre-Split Using Manifest Info

Bulk Load HFilesFull and Incremental

Play WAL of Unconverted Hlogs

Verify Lineage and Restore

Technical Design - Convert


$ hbase backup convert /hbasebackups backup_20140502_2100

full backup : backup_20140501_2100 Incremental backup backup_20140502_2100

/hbasebackups/biginsights/hbasecon_table1/ backup_20140501_2100/Metadata+HFiles backup_20140502_2100/Metadata /hbasebackups/biginsights/hbasecon_table2/ backup_20140501_2100/Metadata+HFiles backup_20140502_2100/Metadata

/hbasebackups/WALs/ backup_20140502_2100/HLogs of ALL Tables

Befor

e

Technical Design - Convert


$ hbase backup convert /hbasebackups backup_20140502_2100

full backup : backup_20140501_2100 Incremental backup backup_20140502_2100

/hbasebackups/biginsights/hbasecon_table1/ backup_20140501_2100/Metadata+HFiles backup_20140502_2100/Metadata+HFiles /hbasebackups/biginsights/hbasecon_table2/ backup_20140501_2100/Metadata+HFiles backup_20140502_2100/Metadata+HFiles

/hbasebackups/WALs/ backup_20140502_2100/

Afte

r

Technical Design - Merge


$ hbase backup merge /hbasebackups biginsights:hbasecon_table1 backup_20140501_2100 backup_20140502_2100

Full backup: backup_20140501_2100 Incremental backup: backup_20140502_2100

/hbasebackups/biginsights/hbasecon_table1/ backup_20140501_2100/ backup_20140502_2100/

/hbasebackups/biginsights/hbasecon_table1/ backup_20140502_2100/

TimeStamp 2

TimeStamp 1

TimeStamp 2

User Interface - CLI$ hbase backup helpUsage: hbase backup COMMANDwhere COMMAND is one of: create create a new backup cancel cancel an ongoing backup delete delete an existing backup describe show the detailed information of a backup history show history of all successful backups status show the status of the latest backup request convert convert incremental backup WAL files into HFiles merge merge backup images stop remove table(s) from backup table set show show table(s) in backup table setEnter 'help COMMAND' to see help message for each command


User Interface – Web UI Backup


User Interface – Web UI Restore


Data Structure - Backup Image • Table Info and Region Info• Backup Manifest

– Table Name– Type: Full or Incremental– Size– Timestamp Info– State Info: Converted, Merged, Compacted, etc.– Dependency Lineage

• Data– HFiles– WALs (For Incremental Backup before convert)


Data Structure - ZooKeeper/backup/hbase startcode {backup marker}

complete/ backupId_1 {contains backup metadata}

…… backupId_n

ongoing {contains the progress status of the current operation} failed {contains error code and message of the current operation} cancel {triggers a cancel operation } incr/ tablelogtimestamp/ table_1 {list of region servers and associated log timestamp for this table} …… table_n last-roll-log-ts/ rs_1 {contains the log timestamp from last roll log} …… rs_n



Sincere gratitude is hereby extended to the following developers who contributed to this effort:

Richard Ding, Jing Chen He, Enoch Hsu, Yu Li, Jihong Ma, Demai Ni, Kan Zhang, Liping Zhang, Xiang Zhou

* ordered by last name

21

Salesforce.com Backups


Jesse Yates

22

Safe harbor statement under the Private Securities Litigation Reform Act of 1995: This presentation may contain forward-looking statements that involve risks, uncertainties, and assumptions. If any such uncertainties materialize or if any of the assumptions proves incorrect, the results of salesforce.com, inc. could differ materially from the results expressed or implied by the forward-looking statements we make. All statements other than statements of historical fact could be deemed forward-looking, including any projections of subscriber growth, earnings, revenues, or other financial items and any statements regarding strategies or plans of management for future operations, statements of belief, any statements concerning new, planned, or upgraded services or technology developments and customer contracts or use of our services.The risks and uncertainties referred to above include – but are not limited to – risks associated with developing and delivering new functionality for our service, our new business model, our past operating losses, possible fluctuations in our operating results and rate of growth, interruptions or delays in our Web hosting, breach of our security measures, risks associated with possible mergers and acquisitions, the immature market in which we operate, our relatively limited operating history, our ability to expand, retain, and motivate our employees and manage our growth, new releases of our service and successful customer deployment, our limited history reselling non-salesforce.com products, and utilization and selling to larger enterprise customers. Further information on potential factors that could affect the financial results of salesforce.com, inc. is included in our annual report on Form 10-K for the most recent fiscal year ended January 31, 2011. This document and others are available on the SEC Filings section of the Investor Information section of our Web site. Any unreleased services or features referenced in this or other press releases or public statements are not currently available and may not be delivered on time or at all. Customers who purchase our services should make the purchase decisions based upon features that are currently available. Salesforce.com, inc. assumes no obligation and does not intend to update these forward-looking statements.


Safe Harbor

Salesforce Environment• Many tenants per cluster• At least 90 days of recovery• DR failover to remote DC• All writes through Phoenix

– Timestamp control


Design Goals• Validate backups regularly• Minimize time to restore a tenant• Validate replication is up to date

• Minimize data storage


Backups• M/R a table at a given point in time

– Point-in-time view of the table• Chunked by file size + tenant (per server)• Chunk manifest

– Chunk info (min/max/hash/tenant ids)


Backups


Key CF CQ TS Value

user1_a fam qual 14 value10

user1_a fam qual 12 Value5

user1_a fam qual 10 Valu2




1. http://phoenix.incubator.apache.org/

Backups


Some HBase Table

M M M M M M M

Hadoop Distributed File System

Backups• Each backup is an incremental

– Lineage by convention• Never write too far back in time• Data retained by custom coprocessor

– Retained up to last successful backup


“Backup isn’t a backup until you’ve restored it and tested it”

-- Some Ops Guy


Restore + Validation• Restore each backup to a new table• Validate that backup has same data a existing

table– Within backup timerange

• Move ‘retained timestamps’ forward


Restore


HDFS

/hbase …/salesforce /backup /somehbasetable /03/14/14 backup.properties chunk1 chunk1.manifest …. chunk1000 chunk1000.manifest

M

M

M

SomeHBaseTable_Restore

Restore• Configurable validation percent

– Start high, move lower

• Backup only valid if restore is successful



90 Days of Backup is LOTS of Data

Even without any duplicates!

Granularity Reduction• Combine backups every ‘period’

– Week, month, 3 months– Specified in table metadata

• Keep latest version of the row• Helpful with lots of updates

– Not useful for unique data (e.g. time series)


Granularity Reduction


HDFS

/salesforce /backup /somehbasetable /03-14-14 /03-13-14 … /03-07-14 /03-01_07-14 /02-23_28-14 /02-16_24-14 /02-09_15-14 /01-14 /12-13 /11-13 /base

M

M

M

HDFS

/salesforce /03-07_14-14 /03-01_07-14

/02-14 /01-14 /12-13

/base

HDFS

Granularity Reduction


HDFS

/salesforce /backup /somehbasetable /03-14-14 /03-13-14 … /03-07-14 /03-01_07-14 /02-23_28-14 /02-16_24-14 /02-09_15-14 /01-14 /12-13 /11-13 /base

M

M

M

Weekly Merge

Monthly Merge

/salesforce /03-07_14-14 /03-01_07-14

/02-14 /01-14 /12-13

/base

Rebuilt Base


Meanwhile…

Remember that DR site?

Disaster Recovery


Primary Data Center Buddy (DR) Data Center

Validation By Backup• Validate replication is working• Validate backup process consistent• Validate granularity reduction consistent


Validation By Backup• Build up hash of hashes

– Two level Merkle Tree• Check that both DCs have the same hash

– Can easily identify differences per-manifest• Requires time-delay for backups

– <= replication delay


Hash Validation


Backup Manifest• chunk size• start time• end time • combined hash• version

Chunk Manifest

• key prefix• stats• hash

Chunk Manifest


…

Primary Data Center

Backup Manifest• chunk size• start time• end time • combined hash• version

Chunk Manifest


Chunk Manifest


…

Buddy Data Center

Mismatch!

Tracking Status• Daily emails• Progress stored in Phoenix Table• Easy access for auditing• Easy display for UI (coming soon)


Future Work• Extensive tooling around per-tenant restore• M/R from snapshot


Lessons Learned• Track Properties

– Version, table, lineage, etc• Fast Restore is Important

– Consider your business case• Validation!


Special ThanksAll the members of the Salesforce HBase team,

particularly:Vasu Mariyala, Sukumar Maddineni, Alex Araujo, Lars

Hofhansl, Ian Varley, Santosh Rau


Summary• Per-Table Backups• IBM

– WAL based– Extra tooling for fast restores– Extensive lineage tracking

• Salesforce– M/R over HTable– Multi-tenant– Multiple Validation vectors



Thanks!Questions?

Jesse Yates Demai NiJing He ChenRichard Ding

HBase Backups

Software

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