Hi Amit,
In the past I have done it like this:
Define a BeanPostProcessor like below. It will go out and get the data from
where ever it lives, convert it to objects and then put them into the
region using a Region reference passed in shortly after the region is
initialized. This bean will need to be in the class path of Geode when it
start up. If using gfsh you can add it to the '--classpath' argument of the
'start server' command.
You can then wire this bean into the Geode Cache xml like so:
<gfe:replicated-region id="Product" />
<bean id="productLoader" class="mypackage.ProductLoader">
<property name="targetBeanName" value="Product" />
</bean>
Note that this bean is placed *below* your region definitions in the spring
cache xml. If I remember correctly order matters and it will try and run
this before the Region reference is created if the order is not correct.
Hope this helps,
Luke
import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.config.BeanPostProcessor;
import org.springframework.util.Assert;
import org.springframework.util.StringUtils;
import com.gemstone.gemfire.cache.Region;
import com.google.gson.Gson;
public class ProductLoader implements BeanPostProcessor {
private String targetBeanName;
protected String getTargetBeanName() {
Assert.state(StringUtils.hasText(targetBeanName), "The target Spring
context bean name was not properly specified!");
return targetBeanName;
}
public void setTargetBeanName(final String targetBeanName) {
Assert.hasText(targetBeanName, "The target Spring context bean name must
be specified!");
this.targetBeanName = targetBeanName;
}
@Override
public Object postProcessBeforeInitialization(final Object bean, final
String beanName) throws BeansException {
return bean;
}
@SuppressWarnings({ "unchecked", "rawtypes" })
@Override
public Object postProcessAfterInitialization(final Object bean, final
String beanName) throws BeansException {
if (beanName.equals(getTargetBeanName()) && bean instanceof Region) {
//get your data from where it lives and do a put or a put all
into the region here
((Region) bean).put(<Key For Product>,<Product Value>);
log.info("Preloading complete. Region now has: " + ((Region)
bean).size());
}
return bean;
}
}
On Sat, Jan 14, 2017 at 10:01 AM, Amit Pandey <[email protected]>
wrote:
> Hey John,
>
> How do we hook up post processors for a region ?
>
> If I have a region like :-
>
> <gfe:partitioned-region id="trades">
> <gfe:cache-loader>
> <bean class="x.y.z.TradeLoader"/>
> </gfe:cache-loader>
> <gfe:cache-writer>
> <bean class="x.y.z.TradeWriter"/>
> </gfe:cache-writer>
>
>
> </gfe:partitioned-region>
>
>
> How do we hook up the post processor?
>
>
> On Tue, Dec 27, 2016 at 1:22 PM, Amit Pandey <[email protected]>
> wrote:
>
>> Hey,
>>
>> Happy Holidays. Wishing you a great new year :)
>>
>> Regards
>>
>> On Tue, Dec 27, 2016 at 1:08 PM, John Blum <[email protected]> wrote:
>>
>>> ;-) Happy holidays my friend. Hope your are getting some good R&R.
>>>
>>> On Mon, Dec 26, 2016 at 2:14 PM, Udo Kohlmeyer <[email protected]>
>>> wrote:
>>>
>>>> it helps a lot! :D
>>>>
>>>> On 12/26/16 12:28, John Blum wrote:
>>>>
>>>> Amit-
>>>>
>>>> Regarding...
>>>>
>>>> *> I want to load all data on cache startup at a go.*
>>>>
>>>> Since you are using "*Spring*", you could easily implement a *Spring*
>>>> BeanPostProcessor [1] (BPP) for each (or all the) *Region(s)* in which
>>>> you need to load data. I do this frequently in *Spring Data
>>>> GemFire/Geode's* test suite when testing *Region* data access
>>>> operations using the GemfireTemplate, *Repositories* or things of that
>>>> nature. Clearly your BPP could use a DataSource to load the data from
>>>> an external data store (e.g. RDBMS).
>>>>
>>>> Another way to do load data on startup is to use a Geode *Initializer*.
>>>> However, this would require you to specify a snippet of cache.xml and
>>>> does not work if you specify your *Regions* in *Spring* (XML/Java)
>>>> config as you should when using *Spring*. I also don't recommend
>>>> using cache.xml, but is the pure, non-*Spring* way to invoke logic
>>>> after the cache has been "fully" initialized (i.e. where the *Regions* have
>>>> been defined in cache.xml).
>>>>
>>>> See here [2] for more details. Note, the documentation talks of
>>>> "launching an application" on startup, after cache initialization, but
>>>> technically, you can do whatever you want, like load data.
>>>>
>>>> I recommend the BPP.
>>>>
>>>>
>>>> *> How should I set it up in config to allow it to join other nodes in
>>>> cluster?*
>>>>
>>>> Regardless of whether your server data node is "embedded" or not, you
>>>> can still use a Locator, or mcast to have the node join the cluster. The
>>>> "embedded" scenario, where the "application" is a GemFire Server data node
>>>> will be part of the cluster as Udo said.
>>>>
>>>> This is easily achievable with...
>>>>
>>>> <util:properties id="gemfireProperties">
>>>> <prop key="name">Example</prop>
>>>> <!-- Set to non-zero value to use Multicast; comment out "locators"
>>>> -->
>>>> <prop key="*mcast-port*">0</prop>
>>>> <prop key="log-level">${gemfire.log-level:config}</prop>
>>>> <prop key=“*locators*”>someHost[10334]</prop>
>>>> <prop key="start-locator">localhost[1034]</prop>
>>>> </util:properties>
>>>>
>>>> <gfe:cache properties-ref="gemfireProperties"/>
>>>>
>>>> ...
>>>>
>>>>
>>>> As you can see from the snippet of *Spring* XML config above, this
>>>> application is a Geode "peer" cache (i.e. embeds a Geode data node/server).
>>>>
>>>> The "*locators*" Geode/GemFire property enables this node to connect
>>>> to a cluster. Likewise, you can use the "*mcast-port*" property
>>>> instead, however, I would recommend *Locators* over mcast.
>>>>
>>>> Additionally, you can see that I specified the "start-locator"
>>>> Geode/GemFire property, which enables me to start an embedded Locator.
>>>> Useful for testing purposes and connecting Geode data nodes together in a
>>>> cluster without a dedicated Locator, though, this approach is less
>>>> resilient if the applications/servers go down (as may be the case in a
>>>> micro-services scenario)!
>>>>
>>>>
>>>> *> if I start with embedded server is it required to use client pool or
>>>> is it not required?*
>>>>
>>>> A "client pool" is only applicable to cache clients (i.e. ClientCaches)
>>>> on the "client-side" of the equation. "peers" find (Locator, mcast) and
>>>> communicate (TCP/UDP, JGroups) with each other through other means once a
>>>> cluster is formed.
>>>>
>>>> In fact, typically, it is more common to position your
>>>> microservices-based applications as Geode cache clients (i.e.
>>>> <gfe:client-cache
>>>> ...>) and have them connect to a dedicated Geode service (i.e. cluster
>>>> of Geode servers/data nodes where also, 1 or more of those nodes are
>>>> running a "CacheServer", listening for cache clients to connect).
>>>> These dedicated Geode server nodes in a cluster constituting the service
>>>> can still be configured with *Spring*, but they typically will not
>>>> contain an application-specific components other than CacheListeners,
>>>> Loaders, Writers, AEQ *Listeners*, etc.
>>>>
>>>> ClientCache applications use 1 or more Pools configured to talk to the
>>>> servers in the cluster (either by way of Locator or direct server
>>>> communication). Pools can be configured with groups to target specific
>>>> members (in that group) in the cluster. Typically, members in 1 group host
>>>> a different set of Regions from another group and is a way to separate data
>>>> traffic from 1 client to another dedicated to a specific resource/purpose
>>>> (usually based on business function, etc).
>>>>
>>>> On a side note, some of what you are wanting to do "scale-wise" seems
>>>> like a perfect fit for Pivotal CloudFoundry, which can auto-scale up or
>>>> down nodes in your cluster based on load and other factors.
>>>>
>>>> Anyway, hope this helps!
>>>>
>>>> -John
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> [1] http://docs.spring.io/spring/docs/current/spring-framewo
>>>> rk-reference/htmlsingle/#beans-factory-extension-bpp
>>>> [2] http://geode.apache.org/docs/guide/basic_config/the_cach
>>>> e/setting_cache_initializer.html
>>>>
>>>>
>>>> On Sun, Dec 25, 2016 at 11:12 PM, Amit Pandey <
>>>> [email protected]> wrote:
>>>>
>>>>> Hey,
>>>>>
>>>>> Thanks.
>>>>>
>>>>> I have lots of reference data which will be loaded at start of day.
>>>>> This data is not bound to change much and as such I want to keep it loaded
>>>>> at the start of day. Read through will make it slow while it is being
>>>>> actually accessed so I want to keep it loaded in memory.
>>>>>
>>>>> Also I want to have functions which will be called by clients to do
>>>>> some compute and return results. Using functions should allow me to add
>>>>> nodes and speed up the compute.
>>>>>
>>>>> I have some micro services each of which will start a gemfire node,
>>>>> and I want to connect, so yes I can set it up with locator.
>>>>>
>>>>> However I have one doubt, if I start with embedded server is it
>>>>> required to use client pool or is it not required?
>>>>>
>>>>> Regards
>>>>>
>>>>> On Mon, Dec 26, 2016 at 1:18 AM, Udo Kohlmeyer <[email protected]>
>>>>> wrote:
>>>>>
>>>>>> Hi there Amit,
>>>>>>
>>>>>> At this stage the only way you could load all data at one go is to
>>>>>> write a client to connect to the db and load all in. Another approach
>>>>>> could
>>>>>> be to write the same code into a function and invoke the function at
>>>>>> start
>>>>>> up. But in both cases both are manual.
>>>>>>
>>>>>> To have geode servers join a cluster, you have 2 ways.
>>>>>>
>>>>>> 1. Connecting them up via a locator
>>>>>> 2. Connecting them up via mcast.
>>>>>>
>>>>>> Please be aware the once you connect a server to a cluster, that
>>>>>> server becomes an integral part of the cluster so adding/removing servers
>>>>>> from a cluster is not something you'd want to do in a load-based scaling
>>>>>> model. i.e if the load is high, add a server and if load is low, shut
>>>>>> down
>>>>>> a server.
>>>>>>
>>>>>> Just interest sake, what is your use case.
>>>>>>
>>>>>> --Udo
>>>>>>
>>>>>> On 12/24/16 05:57, Amit Pandey wrote:
>>>>>>
>>>>>> Hi Guys,
>>>>>>
>>>>>> I am using Spring Data Geode. I have been able to use read and write
>>>>>> through/ write behind. I want to load all data on cache startup at a go.
>>>>>>
>>>>>> Secondly my geode server is embedded but I want to allow it join to
>>>>>> other nodes. How should I set it up in config to allow it to join other
>>>>>> nodes in cluster?
>>>>>>
>>>>>> Regards
>>>>>>
>>>>>>
>>>>>>
>>>>>
>>>>
>>>>
>>>> --
>>>> -John
>>>> john.blum10101 (skype)
>>>>
>>>>
>>>>
>>>
>>>
>>> --
>>> -John
>>> john.blum10101 (skype)
>>>
>>
>>
>
--
Luke Shannon | Platform Engineering | Pivotal
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