diff --git a/src/main/asciidoc/_chapters/faq.adoc b/src/main/asciidoc/_chapters/faq.adoc index 7bffe0e..44af7a8 100644 --- a/src/main/asciidoc/_chapters/faq.adoc +++ b/src/main/asciidoc/_chapters/faq.adoc @@ -44,6 +44,9 @@ How can I find examples of NoSQL/HBase?:: What is the history of HBase?:: See <>. +Why are the cells above 10MB not recommended for HBase?:: + The large cells cannot fit the buffer well in HBase. Large cells bypass the MemStoreLAB per write operation and cannot be cached in the L2 block cache per read operation, HBase has to allocate the on-heap memory once a time. The GC can be very bad. + === Upgrading How do I upgrade Maven-managed projects from HBase 0.94 to HBase 0.96+?:: In HBase 0.96, the project moved to a modular structure. Adjust your project's dependencies to rely upon the `hbase-client` module or another module as appropriate, rather than a single JAR. You can model your Maven dependency after one of the following, depending on your targeted version of HBase. See Section 3.5, “Upgrading from 0.94.x to 0.96.x” or Section 3.3, “Upgrading from 0.96.x to 0.98.x” for more information. diff --git a/src/main/asciidoc/_chapters/hbase_mob.adoc b/src/main/asciidoc/_chapters/hbase_mob.adoc index bdf077a..5da0343 100644 --- a/src/main/asciidoc/_chapters/hbase_mob.adoc +++ b/src/main/asciidoc/_chapters/hbase_mob.adoc @@ -36,7 +36,7 @@ read and write paths are optimized for values smaller than 100KB in size. When HBase deals with large numbers of objects over this threshold, referred to here as medium objects, or MOBs, performance is degraded due to write amplification caused by splits and compactions. When using MOBs, ideally your objects will be between -100KB and 10MB. HBase ***FIX_VERSION_NUMBER*** adds support +100KB and 10MB (see the <>). HBase ***FIX_VERSION_NUMBER*** adds support for better managing large numbers of MOBs while maintaining performance, consistency, and low operational overhead. MOB support is provided by the work done in link:https://issues.apache.org/jira/browse/HBASE-11339[HBASE-11339]. To @@ -155,7 +155,7 @@ family as the second argument. and take a compaction type as the third argument. ---- hbase> compact 't1', 'c1’, ‘MOB’ -hbase> major_compact_mob 't1', 'c1’, ‘MOB’ +hbase> major_compact 't1', 'c1’, ‘MOB’ ---- These commands are also available via `Admin.compact` and