Tuesday, January 14, 2014

Solr Cloud zkCli.sh set clusterstate.json

Well, if you have ever spent two hours doing something completely wrong then you know where I have been today.

I have a Solr Cloud configuration with three shards and no replicas at this time. I am inserting documents then pausing and doing some load tests, then inserting more, until I get to 5 billion.

Well, the linux boxes running Solr and Zookeeper were restarted and Solr was restarted before Zookeeper. Then when Zookeeper was restarted somehow the clusterstate.json was updated so that I now had 1 shard with 2 replicas.

So, all I need to do is fix the clusterstate.json. I stop the Solr instances and go to work. Fortunately I have a copy of the clusterstate.json and I highly recommend saving a copy of your clusterstate.json somewhere safe.

Here is where the trouble starts.

I had found online that you just have to set the clusterstate.json. I assume that you can do this from the zkCli command prompt.

So, I run zkCli.sh and at the prompt I try this:
set /clusterstate.json "`cat /local/path/to/clusterstate.json`"

I get a java NumberFormat Exception.

I tried escaping quotes in the json, removing line feeds, everything I could think of.

Well, long story short, you don't do the command from the zkCli command prompt.

You run the command in your shell/console.

I now do this from the zookeeper bin directory:

#sh zkCli.sh -server set /clusterstate.json "`cat /local/path/to/clusterstate.json`"

Everything worked great.

So, if you are trying to set the clusterstate.json while in ZkCli.sh  you will get this error:

zkcli Command failed: java.lang.NumberFormatException: For input string:

Don't run it inside of ZkCli.sh, run the command from the shell.

Monday, January 13, 2014

Objective C - Iterate over class properties and access property by class type for iOS

I needed a way to add an input accessory on some of my view controllers that have properties for many UITextView and UITextField properties. I didn't want to do it one at a time, I could miss one, or if I added or deleted one I would have to fix that manually as well.

So, I needed a way to walk the properties of my view controller, find all of the UITextView and UITextField properties, and call the method to set the input accessory view.

Here is the resulting code:

+ (NSArray *)allPropertyNamesFor: (id)target
    unsigned count;
    objc_property_t *properties = class_copyPropertyList([target class], &count);
    NSMutableArray *results= [NSMutableArray array];
    unsigned i;
    for (i = 0; i < count; i++)
        objc_property_t property = properties[i];
        NSString *name = [NSString stringWithUTF8String:property_getName(property)];
        [results addObject:name];
    return results;

+ (void) attachToSubViewsOf: (NSObject *) target withAccessoryView: (UIView *)accesoryView {
    NSArray *properties = [self allPropertyNamesFor:target];
    for (NSString *propertyName in properties) {
        SEL sel =  NSSelectorFromString(propertyName);
        if ([target respondsToSelector:sel]) {
            id results = [target performSelector:sel withObject:nil];
            if( ([results isKindOfClass:[UITextView class]]) || ([results isKindOfClass:[UITextField class]]) ) {
                SEL setInputAccessoryViewSel = sel_registerName("setInputAccessoryView:");
                if ([results respondsToSelector:setInputAccessoryViewSel]) {
                    [results performSelector:setInputAccessoryViewSel withObject:accesoryView];